Shareholders' Equity (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	50,000,000				50,000,000				50,000,000
Preferred Stock, Par Value Per Share	$ 0.01				$ 0.01				$ 0.01
Preferred Stock, Shares Issued	4,571,937				4,550,000				4,571,937
Preferred Stock, Liquidation Preference Per Share	$ 25.00								$ 25.00
Preferred Stock, Dividend Payment Terms									The Series A Preferred Stock pays a cumulative cash dividend equivalent to 8.50% of the $25.00 liquidation preference per share each year and the Series B Preferred Stock pays a cumulative cash dividend equivalent to 7.625% of the $25.00 liquidation preference per share each year.
Dividends declared per common share	$ 0.21	$ 0.21	$ 0.21	$ 0.21	$ 0.24	$ 0.24	$ 0.24	$ 0.24
Stock Repurchase Program, Authorized Amount	$ 40,000,000								$ 40,000,000
Stock Repurchase Program Expiration Date									Dec. 31, 2018
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	8,000,000								8,000,000
Preferred Stock, Shares Issued	2,300,000				2,300,000				2,300,000
Preferred Stock, Dividend Rate, Percentage									8.50%
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	7,000,000								7,000,000
Preferred Stock, Shares Issued	2,271,937				2,250,000				2,271,937
Preferred Stock, Dividend Rate, Percentage									7.625%
Preferred Stock
Class of Stock [Line Items]
Dividends Payable, Date to be Paid	Jan. 16, 2017
Dividends Payable, Date of Record	Jan. 01, 2017
Common Stock
Class of Stock [Line Items]
Dividends Payable, Date to be Paid	Jan. 31, 2017
Dividends Payable, Date of Record	Dec. 30, 2016