Summary of Significant Accounting Policies - Stockholders' Equity (Details) - USD ($)			12 Months Ended
	Mar. 31, 2015	Jul. 29, 2014	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Proceeds from issuance of private placement	$ 76,000,000
Proceeds from issuance of private placement, net	68,200,000
Registration costs	7,800,000
Interest paid			$ 7,358,000	$ 3,155,000
Stock redeemed during period, value			19,000,000
Payments for repurchase of redeemable preferred stock			$ 19,000,000	$ 0
Payments for capital contribution to subsidiary bank	36,000,000
Preferred stock authorized (in shares)			200,000
Series C Preferred Stock
Debt Instrument [Line Items]
Stock redeemed during period, value	32,700,000
Payments for repurchase of redeemable preferred stock	19,000,000
Preferred stock authorized (in shares)			0
Preferred stock issued (in shares)			0
Preferred stock, shares outstanding (in shares)			0
Dividends in arrears			$ 0
Stock redeemed (in shares)			32,668
Series A Convertible Preferred Stock
Debt Instrument [Line Items]
Preferred stock authorized (in shares)			0
Preferred stock issued (in shares)			0
Preferred stock, shares outstanding (in shares)			0
Series A Convertible Preferred Stock | Series A Preferred Stock and all dividends in arrears
Debt Instrument [Line Items]
Conversion of stock, shares converted (in shares)		2,762.24
Series D Preferred Stock
Debt Instrument [Line Items]
Preferred stock authorized (in shares)				2,636
Preferred stock issued (in shares)				2,636
Liquidation preference (in dollars per share)				$ 1,000
Preferred stock, dividend rate				12.50%
Series D Preferred Stock | Series A Preferred Stock and all dividends in arrears
Debt Instrument [Line Items]
Conversion of stock, shares issued (in shares)		1,381.12
Series B Preferred Stock
Debt Instrument [Line Items]
Preferred stock authorized (in shares)			1,092
Preferred stock issued (in shares)			268	268
Preferred stock, shares outstanding (in shares)			268	268
Dividend rate (in dollars per share)			$ 60.00
Preferred stock, redemption price (in dollars per share)			$ 1,000
Dividends in arrears			$ 0	$ 88,400
Subordinated debt
Debt Instrument [Line Items]
Interest paid	4,900,000
Secured debt
Debt Instrument [Line Items]
Notes payable, repurchased face amount	10,300,000
Repayments of lines of credit	$ 8,500,000
Private placement offering
Debt Instrument [Line Items]
Number of shares sold (in shares)	6,300,000
Offering price (in dollars per share)	$ 12.00