Consolidated Statements Of Comprehensive Income (Loss) (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Net unrealized holding gains (losses) on investments arising during the period, income tax provision (benefit)	$ (71,081)	$ 22,319	$ (80,282)	$ (15,273)
Reclassification adjustment for net (gains) losses included in net income (loss), income tax provision (benefit)	21	193,537	123,812	192,764
Net change in unrealized holding gains (losses) on investments, income tax provision (benefit)	(71,102)	(171,218)	(204,094)	(208,037)
Net unrealized foreign exchange gains (losses) arising during the period, income tax provision (benefit)	(1,431)	460	(2,501)	1,158
Reclassification adjustment for foreign exchange gains (losses) included in net income (loss), income tax provision (benefit)	0	0	0	0
Net change in unrealized foreign exchange gains (losses), income tax provision (benefit)	(1,431)	460	(2,501)	1,158
Net unrealized gains (losses) on derivatives arising during the period, income tax provision (benefit)	4	0	(85)	0
Reclassification adjustment for derivative gains (losses) included in net income (loss), income tax provision (benefit)	0	0	0	0
Net change in unrealized derivative gains (losses), income tax provision (benefit)	4	0	(85)	0
Net pension and postretirement gain (loss) arising during the period, income tax provision (benefit)	0	0	0	0
Amortization of actuarial net loss included in net periodic pension cost, income tax provision (benefit)	433	(2)	866	(3)
Net change in pension liability and postretirement benefits, income tax provision (benefit)	$ 433	$ (2)	$ 866	$ (3)