Other Comprehensive Income (Loss) (Other Comprehensive Income (Loss) Components And Related Taxes) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Other Comprehensive Income (Loss) [Abstract]
Unrealized gains (losses) on available-for-sale securities, Before-tax amount	$ 17,532,000	$ (5,321,000)
Unrealized gains (losses) on available-for-sale securities, Tax expense (benefit)	6,136,000	(1,862,000)
Unrealized gains (losses) on available-for-sale securities, Net-of-tax amount	11,396,000	(3,459,000)
Reclassification adjustment for gains realized in net income, Before-tax amount	(3,465,000)
Reclassification adjustment for gains realized in net income, Tax expense (benefit)	(1,213,000)
Reclassification adjustment for gains realized in net income, Net-of-tax amount	(2,252,000)
Unrealized net holding gain (loss) on cash flow hedge, Before-tax amount	238,000	(102,000)
Unrealized net holding gain (loss) on cash flow hedge, Tax expense (benefit)	83,000	(36,000)	187,000
Unrealized net holding gain (loss) on cash flow hedge, Net-of-tax amount	155,000	(66,000)	348,000
Other comprehensive income (loss), Before-tax amount	14,305,000	(5,423,000)
Other comprehensive income (loss), Tax expense (benefit)	5,006,000	(1,898,000)
Other comprehensive income (loss), Net-of-tax amount	9,299,000	(3,525,000)
Total comprehensive income	$ 27,600,000	$ 16,100,000	$ 61,000,000	$ 58,200,000