Fair Value Measurements (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Total realized/unrealized gains (losses):
Paydowns received on Level 3 assets measured on a recurring basis	$ 2,100,000	$ 1,500,000
Securities Available-for-Sale
Level 3 Assets Measured on a Recurring Basis
Balance, beginning of period	20,982,000	26,779,000
Total realized/unrealized gains (losses):
Included in other comprehensive income	651,000	(4,168,000)
Settlements	(2,051,000)	(1,520,000)
Other	1,000	(109,000)
Balance, end of period	$ 19,583,000	$ 20,982,000