Business Combinations and Branch Sales - Additional Information (Detail) (USD $)			3 Months Ended		0 Months Ended					3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Core Deposits Minimum	Mar. 31, 2014 Core Deposits Maximum	Jun. 30, 2013 Private Bank of California	Jun. 30, 2013 Private Bank of California Core Deposits Minimum	Jun. 30, 2013 Private Bank of California Core Deposits Maximum	Sep. 10, 2013 The Palisades Group, LLC	Oct. 04, 2013 American West Bank Facility	Mar. 31, 2013 PBOC and CS Financial
Business Acquisition [Line Items]
Agreement date for acquisition					Aug. 21, 2012			Aug. 12, 2013
Business acquisition, purchase price					$ 56,227,000			$ 50,000
Business acquisition, conversion, shares					2,082,654
Business acquisition, shares issued, value					28,282,000
Stock issued, price per share					$ 13.58
Cash paid on merger					25,300,000
Business acquisition, options payout					2,700,000
Pre-merger options fair market value					30,000
Business acquisition, cash price per share					$ 6.52
Business acquisition, each shares of acquired entity convertible into company's shares					0.5379
Preferred stock, converted shares					10,000
Preferred stock, liquidation preference per share					$ 1,000
Preferred stock, shares issued					32,000
Direct acquisition costs					2,600,000
Goodwill	32,868,000	30,143,000			14,763,000
Other intangible assets acquired					10,400,000
Amortization period of other intangible assets			4 years	7 years		2 years	7 years
Provision for loan and lease losses										349,000
Number of branches agreed to sell									8
Deposit premium percentage									2.30%
Deposits held for sale									464,300,000
Gain on branch sale									$ 12,100,000