Fair Value Measurements (Details 3) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Total realized/unrealized gains (losses):
Paydowns received on Level 3 assets measured on a recurring basis	$ 3,600,000	$ 1,600,000
Securities Available-for-Sale
Level 3 Assets Measured on a Recurring Basis
Balance, beginning of period	65,187,000	19,583,000
Total realized/unrealized gains (losses):
Included in other comprehensive income	(199,000)	964,000
Settlements	(3,555,000)	(1,562,000)
Other (1)	52,000	24,000
Balance, end of period	$ 61,485,000	$ 19,009,000