Available-For-Sale And Held-To-Maturity Securities (Narrative) (Details)		3 Months Ended		6 Months Ended
		Jun. 30, 2015 USD ($) security	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) security	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Investments Debt And Equity Securities [Abstract]
Proceeds from sale of available-for-sale securities		$ 552,600,000	$ 66,700,000	$ 552,600,000	$ 66,700,000
Net realized gains resulting from sale of available-for-sale securities		3,100,000	2,000,000	3,100,000	2,000,000
Unrealized gains (losses) recorded in accumulated other comprehensive income	[1],[2]	(1,804,000)	2,704,000	5,873,000	5,567,000
Carrying value of securities pledged as collateral		$ 990,400,000		$ 990,400,000		$ 1,200,000,000
Number of available for sale securities whose amortized costs exceeded their fair values | security		43		43
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses				$ 5,920,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses				3,880,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		$ 275,707,000		$ 275,707,000
Percentage of available-for-sale portfolio		35.00%		35.00%
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security		22		22
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss				$ 3,414,000
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss				3,364,000
Credit-related OTTI		$ 0	$ 0	0	$ 0
Gross unrealized losses related to all other securities	[3]	5,920,000		5,920,000		$ 14,172,000
OTTI on all other securities		$ 0		$ 0

[1] Amounts are net of reclassifications to earnings of realized gains of $1.9 million and $1.2 million for the three months ended June 30, 2015 and 2014, respectively. Amounts are net of reclassifications to earnings of realized gains of $1.9 million and $1.2 million for the six months ended June 30, 2015 and 2014, respectively.

[2] Net of tax benefit of $1.1 million and taxes of $1.7 million for the three months ended June 30, 2015 and 2014, respectively. Net of taxes of $4.8 million and $3.5 million for the six months ended June 30, 2015 and 2014, respectively.

[3] Unrealized gains/(losses) related to available-for-sale securities are reported in accumulated other comprehensive income.