Shareholders' Equity - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended				0 Months Ended							0 Months Ended				0 Months Ended	1 Months Ended
	Nov. 01, 2010	Mar. 31, 2014	Dec. 31, 2013	Jul. 02, 2013 Private Bank of California	Dec. 10, 2013 Common Stock	Jun. 21, 2013 Common Stock Shareholder	Jun. 21, 2013 Common Stock Registered Direct Offering	Jul. 02, 2013 Common Stock Underwriters Over-allotment Option	Jun. 12, 2013 Series C Preferred Stock	Mar. 31, 2014 Series C Preferred Stock	Dec. 31, 2013 Series C Preferred Stock	Jul. 08, 2013 Series C Preferred Stock Underwriters Over-allotment Option	Jun. 12, 2013 Series C Preferred Stock Underwriters Over-allotment Option	Mar. 31, 2014 Series B Preferred Stock	Dec. 31, 2013 Series B Preferred Stock	Nov. 01, 2010 Tcw Shared Opportunity Fund	Nov. 30, 2010 Tcw Shared Opportunity Fund	Nov. 01, 2010 Cor Advisors Llc
Stockholders Equity Note Disclosure [Line Items]
Warrants issued																240,000	240,000	1,395,000
Exercise price of warrants for non-voting common stock																11.00		11.00
Exercisable date of warrants																Nov. 01, 2015
Warrant exercisable period after original vesting date	5 years																5 years
Issuance of stock shares					1,509,450	2,268,000	1,153,846	360,000	1,400,000
Gross proceeds from common stock issued					$ 20.0	$ 29.5	$ 15.0	$ 4.4
Number of institutional investors for which direct offering has been made						2
Underwriters option period								30 days					30 days
Stock issuance and sale, price per share					$ 13.25
Depositary shares representative interest in preferred stock									2.50%
Non cumulative preferred stock, dividend rate									8.00%	8.00%	8.00%
Preferred stock, par value		$ 0.01	$ 0.01						$ 0.01
Preferred stock, liquidation preference per share				$ 1,000					$ 1,000	$ 1,000	$ 1,000			$ 1,000	$ 1,000
Offering price per share									$ 25.00
Gross proceeds from issuance of preferred stock									$ 33.9			$ 5.1
Preferred shares available for issuance												210,000
Preferred stock, converted shares				10,000
Preferred stock, shares issued				32,000						40,250	40,250			10,000	10,000