Stockholders' Equity - Authorized, Issued, and Outstanding Shares (Details) - $ / shares	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Preferred stock
Par Value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Shares authorized (in shares)	5,000,000	5,000,000	5,000,000
Shares issued (in shares)	0	0	0
Shares outstanding (in shares)	0	0	0
Common stock
Par Value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Shares authorized (in shares)	400,000,000	400,000,000	400,000,000
Shares issued (in shares)	288,872,549	289,581,682	293,955,044
Shares outstanding (in shares)	288,872,549	289,581,682	293,955,044