Investments In Affordable Housing (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009
Schedule of Investments [Line Items]
Increase in total assets and liabilities from consolidating affordable housing equity interest	$ 22,800,000	$ 22,800,000
Investments in affordable housing partnerships	78,358,000	88,472,000
Number of limited partnerships in which Company has equity interest	6	6
Minimum compliance period, years	15
Usage of tax credits	9,500,000	10,500,000	11,100,000
Pretax losses	8,200,000	7,600,000	7,300,000
Affordable Housing Limited Partnerships [Member]
Schedule of Investments [Line Items]
Other borrowings for affordable housing limited partnerships	18,900,000	19,100,000
Unfunded commitments for affordable housing limited partnerships	1,500,000	4,300,000
Federal Tax [Member]
Schedule of Investments [Line Items]
Remaining tax credits to be utilized	43,100,000
State Tax [Member]
Schedule of Investments [Line Items]
Remaining tax credits to be utilized	$ 1,200,000