Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 23,210	$ 16,402
Unrealized gains (losses) on securities
Before tax	(3,219)	1,370
Tax effect	1,276	(558)
Net of tax	(1,943)	812
Reclassification of net gains included in net income
Before tax	816	106
Tax effect	(327)	(43)
Net of tax	489	63
Net unrealized gains (losses) on securities	(2,432)	749
Unrealized gains on derivative instruments
Before tax	796	2,121
Tax effect	(316)	(817)
Net of tax	480	1,304
Total other comprehensive income (loss)	(1,952)	2,053
Comprehensive income	$ 21,258	$ 18,455