Summary of Significant Accounting Policies (Details 2)	12 Months Ended
	Dec. 31, 2011 Y
Core deposit intangibles
Goodwill and Intangibles
Minimum useful life (in years)	4
Maximum useful life (in years)	8
Weighted-average amortization period (in years)	4.9
Client advisory contract
Goodwill and Intangibles
Minimum useful life (in years)	4
Maximum useful life (in years)	20
Weighted-average amortization period (in years)	16.5