Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Apr. 28, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Subsequent Event [Line Items]
Preferred stock, shares authorized (shares)		100,000,000		100,000,000
Net proceeds from issuance of preferred stock		$ 24,108	$ 0
Subsequent Event | Series E Preferred Stock
Subsequent Event [Line Items]
Preferred stock, shares authorized (shares)	2,300,000
Preferred stock share price (usd per share)	$ 25.00
Preferred stock, fixed dividend rate, percent	6.45%
Net proceeds from issuance of preferred stock	$ 55,700
Subsequent Event | Series E Preferred Stock | London Interbank Offered Rate (LIBOR)
Subsequent Event [Line Items]
Preferred stock, variable dividend rate, percent	5.14%