CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	162,180,226	174,120,408
Common stock, shares outstanding (in shares)	162,180,226	174,120,408
Preferred Shares
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	40,866,376	40,866,376
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Convertible Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	9,133,624	9,133,624
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0