Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net income	$ 42,399	$ 23,473
Other comprehensive income
Change in unrealized gain (loss) on securities available for sale	(6,171)	1,077
Tax effect and reclassification adjustment	2,179	(391)
Unrealized holding gains (losses) arising during period	(3,992)	686
Non-credit related unrealized loss on other-than-temporarily impaired debt securities	(292)	(2,562)
Tax effect	107	939
Reclassification adjustment for gains (losses) included in net income	(185)	(1,623)
Change in unrealized loss on cash flow hedges	4,405	2,804
Tax effect	(1,609)	(1,106)
Change in unrealized loss on cash flow hedges	2,796	1,698
Adjustment to postretirement benefit obligations	(27)	0
Tax effect	11	0
Adjustment to postretirement benefit obligations, net of tax	(16)	0
Total other comprehensive income (loss)	(1,397)	761
Total comprehensive income	$ 41,002	$ 24,234