Consolidated Statements of Consolidated Comprehensive Income (Loss) (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements of Consolidated Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 72,987	$ (555,664)
Net unrealized gains (losses) on securities:
Net unrealized gains (losses) on securities available for sale arising during period, net of tax (expense) benefit of ($10,103) and $65,136 in 2012 and 2011, respectively	14,629	(96,085)
Reclassification adjustment for realized gains in net income, net of tax expense of $0 and $40,526 in 2012 and 2011, respectively		(61,942)
Postretirement benefit pension plans:
Net loss arising during period, net of tax expense of $690 and $521 for 2012 and 2011, respectively	998	756
Amortization or prior service cost included in net periodic pension cost, net of tax benefit of $122 and $123 in 2012 and 2011, respectively	(179)	(181)
Other comprehensive income (loss)	15,448	(157,452)
Total comprehensive income (loss)	$ 88,435	$ (713,116)