Subsequent Events (Details) - Subsequent event - $ / shares	1 Months Ended
	Feb. 28, 2017	Jan. 31, 2017
Common stock
Subsequent events
Common stock, dividends declared (in dollars per share)	$ 0.2105	$ 0.2105
Class F Preferred Stock
Subsequent events
Preferred stock, dividends declared (in dollars per share)	$ 0.138021	$ 0.138021