CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (unaudited) (USD $) In Thousands	Total	Common stock [Member]	Paid-in capital [Member]	Treasury stock [Member]	Accumulated other comprehensive income (loss) [Member]	Retained earnings [Member]	Comprehensive income (loss) [Member]
Balance at Dec. 31, 2009		$ 130,163	$ 443,294	$ (269,738)	$ 74,155	$ 924,707
Net loss		0	0	0	0	(363,735)	(363,735)
Change in unrealized investment gains and losses, net (notes 7 and 8)		0	0	0	(69,074)	0	(69,074)
Common stock shares issued		74,884	697,492	0	0	0
Reissuance of treasury stock, net		0	(14,425)	47,106	0	(35,410)
Equity compensation		0	12,581	0	0	0
Defined benefit plan adjustments, net		0	0	0	6,390	0	6,390
Unrealized foreign currency translation adjustment		0	0	0	10,665	0	10,665
Comprehensive loss (note 9)		0	0	0	0	0	(415,754)
Balance at Dec. 31, 2010	1,669,055	205,047	1,138,942	(222,632)	22,136	525,562
Net loss	(185,393)	0	0	0	0	(185,393)	(185,393)
Change in unrealized investment gains and losses, net (notes 7 and 8)	24,317	0	0	0	24,317	0	24,317
Reissuance of treasury stock, net		0	(13,534)	59,046	0	(51,304)
Equity compensation		0	6,149	0	0	0
Unrealized foreign currency translation adjustment	4,524	0	0	0	4,524	0	4,524
Comprehensive loss (note 9)	28,841	0	0	0	0	0	(156,552)
Balance at Jun. 30, 2011	$ 1,512,860	$ 205,047	$ 1,131,557	$ (163,586)	$ 50,977	$ 288,865