CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues
Net premiums earned	$ 1,017,131	$ 934,415	$ 2,937,265	$ 2,783,746
Net investment income	95,169	116,923	299,899	257,818
Other insurance related income (losses)	(3,197)	5,944	(4,420)	4,850
Bargain purchase gain	0	0	15,044	0
Net realized investment gains (losses):
Other-than-temporary impairment (OTTI) losses	(5,412)	(4,247)	(13,493)	(20,346)
Other realized investment gains (losses)	20,044	9,452	(1,318)	(19,949)
Total net realized investment gains (losses)	14,632	5,205	(14,811)	(40,295)
Total revenues	1,123,735	1,062,487	3,232,977	3,006,119
Expenses
Net losses and loss expenses	1,235,367	532,328	2,447,640	1,663,584
Acquisition costs	194,724	189,810	588,879	559,570
General and administrative expenses	124,629	142,906	433,704	439,554
Foreign exchange losses (gains)	32,510	(13,795)	90,093	(69,781)
Interest expense and financing costs	12,835	12,839	38,377	38,586
Transaction related expenses	5,970	0	5,970	0
Total expenses	1,606,035	864,088	3,604,663	2,631,513
Income (loss) before income taxes and interest in income (loss) of equity method investments	(482,300)	198,399	(371,686)	374,606
Income tax (expense) benefit	25,877	(9,352)	38,547	(7,712)
Interest in loss of equity method investments	(661)	(2,434)	(8,402)	(2,434)
Net income (loss)	(457,084)	186,613	(341,541)	364,460
Preferred share dividends	10,656	9,969	36,154	29,906
Net income (loss) available to common shareholders	$ (467,740)	$ 176,644	$ (377,695)	$ 334,554
Net income (loss) per common share:
Basic net income (loss) (in usd per share)	$ (5.61)	$ 1.97	$ (4.47)	$ 3.64
Diluted net income (loss) (in usd per share)	$ (5.61)	$ 1.96	$ (4.47)	$ 3.61
Weighted average number of common shares outstanding - basic (in shares)	83,305	89,621	84,479	91,852
Weighted average number of common shares outstanding - diluted (in shares)	83,305	90,351	84,479	92,579
Cash dividends declared per common share (in usd per share)	$ 0.38	$ 0.35	$ 1.14	$ 1.05