| At and For the Year Ended December 31, (in millions, except per share amounts) | 2018 | 2017 | 2016 | 2015 | 2014 |
| Selected Statement of Operations Data: | |||||
| Gross premiums written | $6,910.1 | $5,556.3 | $4,970.2 | $4,603.7 | $4,711.5 |
| Net premiums written | 4,659.0 | 4,027.1 | 3,753.0 | 3,674.7 | 3,907.0 |
| Net premiums earned | 4,791.5 | 4,148.8 | 3,705.6 | 3,686.4 | 3,871.0 |
| Net investment income | 438.5 | 400.8 | 353.3 | 305.3 | 342.8 |
| Net investment gains (losses) | (150.2) | 28.2 | (60.5) | (138.5) | 132.1 |
| Net income (loss) available to common shareholders(1)(2)(3)(4)(5) | 0.4 | (415.8) | 465.5 | 601.6 | 770.7 |
| Operating income (loss)(1)(2)(4)(5)(6) | 161.4 | (264.6) | 409.9 | 400.5 | 562.9 |
| Ex-PGAAP operating income (loss)(13) | 209.2 | (248.4) | nm | nm | nm |
| Per Common Share Data: | |||||
| Earnings (loss) per diluted common share | - | (4.94) | 5.08 | 6.04 | 7.29 |
| Operating income (loss) per diluted common share(7) | 1.92 | (3.15) | 4.48 | 4.02 | 5.32 |
| Ex-PGAAP operating income (loss) per diluted common share(13) | 2.49 | (2.95) | nm | nm | nm |
| Book value per common share(8)(9) | 50.91 | 54.91 | 59.54 | 55.32 | 52.23 |
| Book value per diluted common share(8)(9) | 49.93 | 53.88 | 58.27 | 54.08 | 50.63 |
| Cash dividends declared per common share | 1.57 | 1.53 | 1.43 | 1.22 | 1.10 |
| Operating Ratios:(10) | |||||
| Net loss and loss expense ratio | 66.6% | 79.2% | 59.5% | 59.0% | 56.5% |
| Expense ratio | 33.3% | 33.9% | 36.4% | 35.7% | 35.1% |
| Acquisition cost ratio | 20.2% | 19.9% | 20.2% | 19.5% | 19.0% |
| General and administrative expense ratio | 13.1% | 14.0% | 16.2% | 16.2% | 16.1% |
| Combined ratio | 99.9% | 113.1% | 95.9% | 94.7% | 91.6% |
| Selected Balance Sheet Data: | |||||
| Total assets | $24,132.6 | $24,760.2 | $20,813.7 | $19,981.9 | $19,955.7 |
| Senior notes and notes payable | 1,342.0 | 1,376.5 | 993.0 | 991.8 | 990.8 |
| Preferred shares | 775.0 | 775.0 | 1,126.1 | 627.8 | 627.8 |
| Common equity | 4,255.1 | 4,566.3 | 5,146.3 | 5,239.0 | 5,193.3 |
| Total shareholders’ equity attributable to AXIS Capital | 5,030.1 | 5,341.3 | 6,272.4 | 5,866.9 | 5,821.1 |
| Total capital(11) | 6,372.1 | 6,717.8 | 7,265.4 | 6,858.7 | 6,811.9 |
| Return on average common shareholders’ equity (“ROACE”) | 0.0% | (8.6%) | 9.0% | 11.5% | 14.8% |
| Operating ROACE(12) | 3.7% | (5.4%) | 7.9% | 7.7% | 10.8% |
| Ex-PGAAP Operating ROACE(12) | 4.7% | (5.1%) | nm | nm | nm |
nm = not meaningful
(1) During 2018 and 2017, the Company recognized transaction and reorganization expenses of $67 million and $27 million, respectively, related to the Company’s transformation program which was launched in 2017. This program encompasses the integration of Novae Group plc (“Novae”) which commenced in the fourth quarter of 2017, the realignment of the Company’s accident and health business, together with other initiatives designed to increase efficiency and enhance profitability while delivering a customer-centric operating model.
(2) During 2017, the Company recognized a tax expense of $42 million due to the revaluation of net deferred tax assets pursuant to the U.S. Tax Reform.
(3) During 2018 and 2017, the Company recognized amortization of value of business acquired (“VOBA”) of $171 million and $50 million, respectively, related to the acquisition of Novae.
(4) During 2015, the Company accepted a request from PartnerRe Ltd., a Bermuda exempted company (“PartnerRe”) to terminate the Agreement and Plan of Amalgamation (the “Amalgamation Agreement”) with the Company. PartnerRe paid the Company a termination fee of $280 million.
(5) During 2015, the Company implemented a number of profitability enhancement initiatives, which resulted in recognition of transaction and reorganization expenses of $46 million and general and administrative expenses of $5 million.
(6) Operating income (loss) is a non-GAAP financial measure as defined in Item 10(e) of SEC Regulation S-K. The reconciliation to net income (loss) available (attributable) to common shareholders, the most comparable GAAP financial measure, is provided later in this report.
(7) Operating income (loss) per diluted common share is a non-GAAP financial measure as defined in Item 10(e) of SEC Regulation S-K. The reconciliation to earnings (loss) per diluted common share, the most comparable GAAP financial measure, is provided later in this report.
(8) Book value per common share and book value per diluted common share are based on total common shareholders’ equity divided by common shares and diluted common shares outstanding, respectively.
(9) Calculations and share amounts at December 31, 2015 include 1,358,380 additional shares delivered to the Company in January 2016 under the Company’s Accelerated Share Repurchase (“ASR”) agreement entered into on August 17, 2015.
(10) Operating ratios are calculated by dividing the respective operating expenses by net premiums earned.
(11) Total capital represents the sum of total shareholders’ equity attributable to AXIS Capital plus senior notes and notes payable.
(12) Operating ROACE is calculated by dividing operating income (loss) for the year by the average shareholders’ equity determined by using the common shareholders’ equity balances at the beginning and end of the year. Operating ROACE is a non-GAAP financial measure as defined in Item 10(e) of SEC Regulation S-K. The reconciliation to ROACE, the most comparable GAAP financial measure, is provided later in this report.
(13) Ex-PGAAP operating income (loss), ex-PGAAP operating income (loss) per diluted common share and ex-PGAAP return on average common equity (“ex-PGAAP operating ROACE”) are non-GAAP financial measures as defined in Item 10(e) of SEC Regulation S-K. The reconciliation to net income (loss) available (attributable) to common shareholders, earnings per diluted common share, and return on average common equity, respectively, the most comparable GAAP financial measures are provided later in this report.