Fair Value Measurements (Details 3) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Total realized/unrealized gains (losses):
Paydowns received on Level 3 assets measured on a recurring basis	$ 1,600,000	$ 1,700,000
Securities Available-for-Sale
Level 3 Assets Measured on a Recurring Basis
Balance, beginning of period	19,583,000	20,982,000
Total realized/unrealized gains (losses):
Included in other comprehensive income	964,000	1,690,000
Settlements	(1,562,000)	(1,707,000)
Other	24,000	(53,000)
Balance, end of period	$ 19,009,000	$ 20,912,000