Securities (Summary of Fair Values and Unrealized Losses of Securities, Segregated by Length of Impairment) (Details) (USD $) In Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Securities available for sale, Less than 12 Months, Fair Value	$ 58,867	$ 147,102
Securities available for sale, Less than 12 Months, Unrealized Losses	(93)	(968)
Securities available for sale, Greater than 12 Months, Fair Value	13,187	13,843
Securities available for sale, Greater than 12 Months, Unrealized Losses	(13,633)	(15,055)
Securities available for sale, Fair Value, Total	72,054	160,945
Securities available for sale, Unrealized Losses, Total	(13,726)	(16,023)
Securities held to maturity, Less than 12 Months, Fair Value	224,483	245,294
Securities held to maturity, Less than 12 Months, Unrealized Losses	(2,031)	(5,395)
Securities held to maturity, Greater than 12 Months, Fair Value	12,713	16,700
Securities held to maturity, Greater than 12 Months, Unrealized Losses	(1,420)	(2,354)
Securities held to maturity, Fair Value, Total	237,196	261,994
Securities held to maturity, Unrealized Losses, Total	(3,451)	(7,749)
U.S. Treasury and Other U.S. Government Agencies and Corporations [Member]
Securities available for sale, Less than 12 Months, Fair Value	57,646	117,140
Securities available for sale, Less than 12 Months, Unrealized Losses	(91)	(688)
Securities available for sale, Fair Value, Total	57,646	117,140
Securities available for sale, Unrealized Losses, Total	(91)	(688)
Agency Mortgage Backed Securities [Member]
Securities held to maturity, Less than 12 Months, Fair Value	180,079	156,544
Securities held to maturity, Less than 12 Months, Unrealized Losses	(1,556)	(3,079)
Securities held to maturity, Fair Value, Total	180,079	156,544
Securities held to maturity, Unrealized Losses, Total	(1,556)	(3,079)
Agency Collateralized Mortgage Obligations [Member]
Securities available for sale, Less than 12 Months, Fair Value		22,616
Securities available for sale, Less than 12 Months, Unrealized Losses		(192)
Securities available for sale, Fair Value, Total		22,616
Securities available for sale, Unrealized Losses, Total		(192)
Securities held to maturity, Less than 12 Months, Fair Value	27,885	39,074
Securities held to maturity, Less than 12 Months, Unrealized Losses	(164)	(889)
Securities held to maturity, Fair Value, Total	27,885	39,074
Securities held to maturity, Unrealized Losses, Total	(164)	(889)
Non-Agency Collateralized Mortgage Obligations [Member]
Securities held to maturity, Less than 12 Months, Fair Value		2,551
Securities held to maturity, Less than 12 Months, Unrealized Losses		(12)
Securities held to maturity, Greater than 12 Months, Fair Value	9,395	10,739
Securities held to maturity, Greater than 12 Months, Unrealized Losses	(908)	(1,319)
Securities held to maturity, Fair Value, Total	9,395	13,290
Securities held to maturity, Unrealized Losses, Total	(908)	(1,331)
States Of The U.S. And Political Subdivisions [Member]
Securities available for sale, Less than 12 Months, Fair Value	1,193	3,322
Securities available for sale, Less than 12 Months, Unrealized Losses	(1)	(26)
Securities available for sale, Fair Value, Total	1,193	3,322
Securities available for sale, Unrealized Losses, Total	(1)	(26)
Securities held to maturity, Less than 12 Months, Fair Value	16,519	47,125
Securities held to maturity, Less than 12 Months, Unrealized Losses	(311)	(1,415)
Securities held to maturity, Greater than 12 Months, Fair Value		2,319
Securities held to maturity, Greater than 12 Months, Unrealized Losses		(215)
Securities held to maturity, Fair Value, Total	16,519	49,444
Securities held to maturity, Unrealized Losses, Total	(311)	(1,630)
Collateralized Debt Obligations [Member]
Securities available for sale, Greater than 12 Months, Fair Value	6,605	5,974
Securities available for sale, Greater than 12 Months, Unrealized Losses	(12,683)	(13,314)
Securities available for sale, Fair Value, Total	6,605	5,974
Securities available for sale, Unrealized Losses, Total	(12,683)	(13,314)
Securities held to maturity, Greater than 12 Months, Fair Value	1,994	2,354
Securities held to maturity, Greater than 12 Months, Unrealized Losses	(508)	(778)
Securities held to maturity, Fair Value, Total	1,994	2,354
Securities held to maturity, Unrealized Losses, Total	(508)	(778)
Other Debt Securities [Member]
Securities available for sale, Less than 12 Months, Fair Value		4,024
Securities available for sale, Less than 12 Months, Unrealized Losses		(62)
Securities available for sale, Greater than 12 Months, Fair Value	5,946	7,221
Securities available for sale, Greater than 12 Months, Unrealized Losses	(913)	(1,682)
Securities available for sale, Fair Value, Total	5,946	11,245
Securities available for sale, Unrealized Losses, Total	(913)	(1,744)
Securities held to maturity, Greater than 12 Months, Fair Value	1,324	1,288
Securities held to maturity, Greater than 12 Months, Unrealized Losses	(4)	(42)
Securities held to maturity, Fair Value, Total	1,324	1,288
Securities held to maturity, Unrealized Losses, Total	(4)	(42)
Equity Securities [Member]
Securities available for sale, Less than 12 Months, Fair Value	28
Securities available for sale, Less than 12 Months, Unrealized Losses	(1)
Securities available for sale, Greater than 12 Months, Fair Value	636	648
Securities available for sale, Greater than 12 Months, Unrealized Losses	(37)	(59)
Securities available for sale, Fair Value, Total	664	648
Securities available for sale, Unrealized Losses, Total	$ (38)	$ (59)