Business Combinations (Details) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended			1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Jul. 31, 2012 Rochdale Investment Management, LLC	Dec. 31, 2012 Rochdale Investment Management, LLC	Jul. 02, 2012 Rochdale Investment Management, LLC	Jul. 02, 2012 Rochdale Investment Management, LLC Client Contract	Apr. 30, 2012 First American Equipment Finance	Jun. 30, 2011 Nevada Commerce Bank	Dec. 31, 2012 Nevada Commerce Bank	Apr. 08, 2011 Nevada Commerce Bank
Business acquisitions
Assets under management by acquired firm, Rochdale Investment Management, LLC						$ 4,890,000,000
Carrying value of assets acquired								343,000,000			138,900,000
Carrying value of liabilities assumed								325,000,000			121,900,000
Fair value of acquired lease receivables								318,300,000
Borrowings and nonrecourse debt								320,900,000
Acquired goodwill						86,500,000		68,400,000
Customer contract intangible							19,000,000
Recognized contingent consideration liability at fair value						46,700,000
Low-end of the potential range of estimate of total consideration payment						32,000,000
High-end of the potential range of estimate of total consideration payment						74,000,000
Period of additional cash consideration payment				6 years
Acquisition related expense					2,000,000			600,000
Covered loans	55,313,000	330,566,000									56,400,000
Covered other real estate owned	7,463,000	15,161,000									7,500,000
Deposits	(126,795,000)	(541,499,000)									118,400,000
Cash from the FDIC											2,700,000
Gain on acquisition	8,164,000	27,339,000							8,200,000
FDIC reimbursement (as a percent)										80.00%
Term of loss-sharing agreements for single family residential loans										10 years
Term of loss-sharing agreements for other loans										8 years
FDIC indemnification asset	$ 204,259,000		$ 150,018,000								$ 33,800,000