Fair Value Measurements (Narrative) (Details) (USD $)	12 Months Ended							12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Level 3 [Member] security	Dec. 31, 2011 Level 3 [Member] security	Dec. 31, 2012 Nonrecurring [Member]	Dec. 31, 2011 Nonrecurring [Member]	Dec. 31, 2012 Nonrecurring [Member] Level 3 [Member]	Dec. 31, 2011 Nonrecurring [Member] Level 3 [Member]	Sep. 30, 2011 Nonrecurring [Member] Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, amortized cost	$ 48,370,000	$ 19,624,000
Mortgage loans held for sale, fair value	50,056,000	20,340,000
Mortgage loans held for sale difference between fair value and principal amount	1,700,000	716,000
Number of pooled trust preferred debt securities				2	2
Collateral dependent impaired loans						9,550,000	10,391,000	9,550,000	10,391,000
Allowance for loan loss on collateral dependent impaired loans								2,000,000		1,400,000
Fair value of property acquired through foreclosures or repossessions transferred from loans	3,167,000	2,031,000	3,255,000					3,167,000	2,000,000
Valuation adjustments charged to allowance on property acquired through foreclosure or repossession								410,000	328,000
Valuation adjustments charged to earnings on property acquired through foreclosure or repossession								$ 350,000	$ 642,000