CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net income	$ 39,447	$ 35,357	$ 106,798	$ 108,836
Other comprehensive (loss) income, net of tax:
Net gains (losses) arising during the period	202	(4,102)	7,323	3,784
Less reclassification adjustment for net gains included in net income	(911)	(493)	(1,519)	(12,214)
Total	(709)	(4,595)	5,804	(8,430)
Non-credit impairment losses on available for sale securities
Net change in non-credit impairment losses on securities	(2,161)	(312)	9,497	281
Less reclassification adjustment for credit impairment losses included in net income	2,415	(68)	2,488	293
Total	254	(380)	11,985	574
Unrealized gains and losses on derivatives (cash flow hedges)
Net losses on derivatives arising during the period	(1,219)	(9,185)	(3,389)	(12,145)
Less reclassification adjustment for net losses included in net income	1,038	353	2,657	1,042
Total	(181)	(8,832)	(732)	(11,103)
Defined benefit pension plan
Amortization of prior service cost	102	93	308	278
Amortization of net loss	338	200	1,013	598
Total	440	293	1,321	876
Total other comprehensive (loss) income	(196)	(13,514)	18,378	(18,083)
Total comprehensive income	$ 39,251	$ 21,843	$ 125,176	$ 90,753