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	$ 45,648	$ 37,793	$ 88,047	$ 61,266
Other comprehensive income
Change in unrealized gain (loss) on securities available for sale	(53,120)	5,247	(59,291)	6,793
Tax effect and reclassification adjustment	19,177	(1,866)	21,357	(2,490)
Unrealized holding gains (losses) arising during period	(33,943)	3,381	(37,934)	4,303
Non-credit related unrealized loss on other-than-temporarily impaired debt securities	433	4,676	141	1,741
Tax effect	(159)	(1,714)	(52)	(638)
Reclassification adjustment for gains (losses) included in net income	274	2,962	89	1,103
Change in unrealized gain (loss) on cash flow hedges	10,081	(6,579)	14,486	(3,775)
Tax effect	(3,679)	2,401	(5,287)	1,295
Change in unrealized loss on cash flow hedges	6,402	(4,178)	9,199	(2,480)
Adjustment to postretirement benefit obligations	0	0	(27)	0
Tax effect	0	0	9	0
Adjustment to postretirement benefit obligations, net of tax	0	0	(18)	0
Total other comprehensive income (loss)	(27,267)	2,165	(28,664)	2,926
Total comprehensive income	$ 18,381	$ 39,958	$ 59,383	$ 64,192