Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net income (loss)	$ 33,483	$ 124,610	$ 83,533	$ 98,024
Unrealized (losses) gains on investments available-for-sale:
Unrealized holding (losses) gains arising during the period	(65,763)	20,663	(74,853)	27,572
Less: Reclassification adjustments for gains included in earnings	(5,647)	(12,431)	(22,936)	(25,389)
Unrealized (losses) gains on investments available-for-sale, net	(71,410)	8,232	(97,789)	2,183
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	1,286	2,076
Defined benefit pension plans, net	643	1,038	1,286	2,076
Other comprehensive (loss) income before tax	(70,767)	9,270	(96,503)	4,259
Income tax (benefit) expense related to components of other comprehensive income	(24,882)	12,814	(33,910)	13,215
Other comprehensive loss, net of tax	(45,885)	(3,544)	(62,593)	(8,956)
Comprehensive (loss) income	$ (12,402)	$ 121,066	$ 20,940	$ 89,068