Stockholders' Equity (Details 2) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Dividends
Common stock dividends declared (in dollars per share)	$ 1.41	$ 0.51	$ 0.10
Dividends declared (in dollars per share)	3.41	2.51	2.60
Dividends payable with a combination of cash and stock (in dollars per share)	$ 1.26	$ 0.36
Series A Cumulative Redeemable Preferred Stock
Dividends
Preferred stock dividends declared (in dollars per share)			0.50
Series D Cumulative Redeemable Preferred Stock
Dividends
Preferred stock dividends declared (in dollars per share)	$ 2.00	$ 2.00	$ 2.00