Shareholders' Equity (Details) - $ / shares	Aug. 24, 2015	May. 18, 2015	Sep. 30, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Preferred stock, par value (usd per share)			$ 1.0	$ 1.00
Preferred stock, liquidation preference (usd per share)			$ 25.00	$ 25.00
Series C Preferred Stock
Class of Stock [Line Items]
Issuance of preferred stock, net of offering costs, shares		2,300,000
Preferred stock, par value (usd per share)		$ 1.00
Preferred stock, liquidation preference (usd per share)		$ 25.00
Preferred stock, fixed dividend rate, percent		7.00%
Preferred stock, redemption price (usd per share)		$ 25.00
Preferred stock, dividend declared (usd per share)	$ 0.56875
Series C Preferred Stock | London Interbank Offered Rate (LIBOR)
Class of Stock [Line Items]
Preferred stock, variable dividend rate, percent		5.30%