Consolidated Statement of Stockholders' Equity - 9 months ended Sep. 30, 2016 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2015	$ 1,096,148	$ 1,793	$ 357,829	$ (155,801)	$ 868,723	$ 23,604
Beginning balance (in shares) at Dec. 31, 2015	17,942,269	17,942,269		3,511,380
Net income	$ 61,135				61,135
Dividends paid	(2,619)				(2,619)
Changes in comprehensive income:
Change in net unrealized gain (loss) on investments	44,811					44,811
Change in net non-credit other-than-temporary impairment losses	(64)					(64)
Change in foreign currency translation gain (loss)	(6,174)					(6,174)
Other comprehensive income (loss)	38,573					38,573
Shares issued under stock plan	(2,885)	$ 13	(2,898)
Shares issued under stock plan (in shares)		128,546
Share-based compensation	13,929		13,929
Ending balance at Sep. 30, 2016	$ 1,204,281	$ 1,806	$ 368,860	$ (155,801)	$ 927,239	$ 62,177
Ending balance (in shares) at Sep. 30, 2016	18,070,815	18,070,815		3,511,380