Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income (loss)	$ 66,840	$ 18,028	$ 150,373	$ 116,052
Unrealized gains (losses) on investments available-for-sale:
Unrealized holding gains (losses) arising during the period	1,074	36,554	(73,779)	64,126
Less: Reclassification adjustments for gains included in earnings	(370)	(4,272)	(23,306)	(29,661)
Unrealized gains (losses) on investments available-for-sale, net	704	32,282	(97,085)	34,465
Defined benefit pension plans:
Prior service cost arising during the period	0	0	0	0
Net loss arising during the period	0	0	0	0
Less: Amortization of prior service cost and net loss included in net periodic pension cost	643	1,038	1,929	3,114
Defined benefit pension plans, net	643	1,038	1,929	3,114
Other comprehensive income (loss) before tax	1,347	33,320	(95,156)	37,579
Income tax expense (benefit) related to components of other comprehensive income	433	13,065	(33,477)	26,280
Other comprehensive income (loss), net of tax	914	20,255	(61,679)	11,299
Comprehensive income	$ 67,754	$ 38,283	$ 88,694	$ 127,351