Subsequent Events (Details) - $ / shares		6 Months Ended
	Jul. 28, 2016	Jun. 30, 2016	Jun. 30, 2015
Subsequent Events
Quarterly cash dividends declared to holders of common stock		$ 0.18	$ 0.16
Subsequent Event
Subsequent Events
Quarterly cash dividends declared to holders of common stock	$ 0.09
Subsequent Event | Series C convertible perpetual preferred stock
Subsequent Events
Quarterly cash dividends declared to holders of Series C preferred stock (on an as converted basis)	$ 0.09