Consolidated Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net income	$ 55,585	$ 35,495
Unrealized gains on securities:
Change in unrealized securities gains arising during period	(1,418)	(2,898)
Deferred tax benefit (expense)	542	1,123
Reclassification adjustment for losses (gains) included in income before income taxes	(58)	0
Deferred tax expense (benefit)	23	0
Total change in unrealized gains on securities, net of tax	(911)	(1,775)
Change in fair value of cash flow hedges:
Change in unrecognized loss on cash flow hedges	2	(359)
Deferred tax benefit (expense)	(1)	141
Reclassification adjustment for gains (losses) included in income before income taxes	813	749
Deferred tax benefit	(321)	(296)
Total change in unrecognized loss on cash flow hedges, net of tax	493	235
Change in pension obligation:
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Net of Tax	4,304	2,790
Deferred tax expense	(1,685)	(1,092)
Total change in pension obligation, net of tax	(2,619)	(1,698)
Net current period other comprehensive income	2,201	158
Total comprehensive income	$ 57,786	$ 35,653