CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2016	Dec. 31, 2015
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	117,500,000	117,500,000
Common stock, shares issued	34,154,044	34,733,117
Common stock, shares outstanding	34,154,044	34,733,117
2.5 Percent Convertible Notes
Convertible notes, interest rate (as a percent)	2.50%	2.50%