Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net income	$ 65,142	$ 82,803	$ 114,272	$ 247,164
Unrealized holding gains (losses) arising during the period
Unrealized holding gains (losses) arising during the period	6,239	6,943	33,845	86,614
Less: Reclassification adjustment for net gains (losses) included in net income (loss)	111	3,695	(2,687)	2,296
Net unrealized gains (losses) on investments	6,128	3,248	36,532	84,318
Net foreign currency translation adjustments	28	(36)	136	(346)
Net actuarial gains (losses)	0	156	0	(22)
Other comprehensive income, net of tax	6,156	3,368	36,668	83,950
Foreign currency translation adjustments:
Comprehensive income	$ 71,298	$ 86,171	$ 150,940	$ 331,114