Declaration of Dividends (Details) (USD $)	3 Months Ended			6 Months Ended		3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014 Subsequent Event [Member]	Jun. 30, 2014 Series C Preferred Stock [Member]	Mar. 31, 2014 Series C Preferred Stock [Member]	Sep. 30, 2014 Series C Preferred Stock [Member] Subsequent Event [Member]
Dividends Payable [Line Items]
Dividends on common stock (in dollars per share)	$ 0.09	$ 0.08	$ 0.08	$ 0.17	$ 0.15	$ 0.09
Dividends payable recorded date	Jun. 13, 2014	Mar. 14, 2014				Sep. 15, 2014	Jul. 01, 2014	Apr. 01, 2014	Oct. 01, 2014
Dividends payable declared date	May 21, 2014	Jan. 15, 2014				Jul. 16, 2014	May 21, 2014	Jan. 15, 2014	Jul. 16, 2014
Dividends payable, date to be paid	Jul. 01, 2014	Apr. 01, 2014				Oct. 01, 2014	Jul. 15, 2014	Apr. 15, 2014	Oct. 15, 2014
Preferred stock dividend rate (in hundredth)							1.00%	1.00%	1.00%