CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2011	$ 803,435	$ 1,746	$ 322,133	$ (155,801)	$ 565,109	$ 70,248
Beginning Balance (in shares) at Dec. 31, 2011		17,467,615		3,511,380
Net income	35,718				35,718
Changes in comprehensive income:
Change in net unrealized gain (loss) on investments	30,368					30,368
Change in net non-credit other-than-temporary impairment losses	912					912
Change in foreign currency translation gain (loss)	(694)					(694)
Other comprehensive income (loss)	30,586					30,586
Shares issued under stock plan (in shares)		80,497
Shares issued under stock plan	68	8	60
Share-based compensation	5,004		5,004
Ending Balance at Sep. 30, 2012	$ 874,811	$ 1,754	$ 327,197	$ (155,801)	$ 600,827	$ 100,834
Ending Balance (in shares) at Sep. 30, 2012		17,548,112		3,511,380