Fair Value Measurements (Summary of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Beginning balance	$ 198,706,000	$ 203,220,000	$ 204,301,000	$ 212,771,000
Total gains or losses (realized /unrealized) included in earnings	2,600,000	(120,000)	3,662,000	(2,749,000)
Total gains or losses (realized /unrealized) included in other comprehensive income	(340,000)	(4,920,000)	(1,611,000)	(13,407,000)
Investment securities called	(1,025,000)	(1,175,000)	(6,943,000)	(2,550,000)
Discount accretion	98,000	127,000	405,000	264,000
Capitalized interest/dividends	1,000	(42,000)	44,000	167,000
Purchase of private equity securities	3,060,000	1,200,000	3,239,000	3,904,000
Purchase of risk participation agreement			79,000
Sale of risk participation agreement	(275,000)		(351,000)	(110,000)
Ending balance	202,825,000	198,290,000	202,825,000	198,290,000
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	2,713,000	70,000	4,144,000	(2,541,000)
State and Municipal Obligations [Member]
Beginning balance	143,207,000	158,111,000	150,089,000	167,836,000
Total gains or losses (realized /unrealized) included in earnings
Total gains or losses (realized /unrealized) included in other comprehensive income	(340,000)	(4,920,000)	(1,611,000)	(13,407,000)
Investment securities called	(1,025,000)	(1,175,000)	(6,943,000)	(2,550,000)
Discount accretion	98,000	127,000	405,000	264,000
Capitalized interest/dividends
Purchase of private equity securities
Purchase of risk participation agreement
Sale of risk participation agreement
Ending balance	141,940,000	152,143,000	141,940,000	152,143,000
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end
Derivatives [Member]
Beginning balance	(8,000)	(15,000)	352,000	108,000
Total gains or losses (realized /unrealized) included in earnings	(5,000)	(95,000)	(368,000)	(108,000)
Total gains or losses (realized /unrealized) included in other comprehensive income
Investment securities called
Discount accretion
Capitalized interest/dividends
Purchase of private equity securities
Purchase of risk participation agreement			79,000
Sale of risk participation agreement	(275,000)		(351,000)	(110,000)
Ending balance	(288,000)	(110,000)	(288,000)	(110,000)
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	108,000	95,000	114,000	100,000
Private Equity Investments [Member]
Beginning balance	55,507,000	45,124,000	53,860,000	44,827,000
Total gains or losses (realized /unrealized) included in earnings	2,605,000	(25,000)	4,030,000	(2,641,000)
Total gains or losses (realized /unrealized) included in other comprehensive income
Investment securities called
Discount accretion
Capitalized interest/dividends	1,000	(42,000)	44,000	167,000
Purchase of private equity securities	3,060,000	1,200,000	3,239,000	3,904,000
Purchase of risk participation agreement
Sale of risk participation agreement
Ending balance	61,173,000	46,257,000	61,173,000	46,257,000
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	$ 2,605,000	$ (25,000)	$ 4,030,000	$ (2,641,000)