Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 874	$ 1,189
Cumulative convertible preferred stock, at par value (in dollars per share)	$ 0.0001	$ 0.0001
Cumulative convertible preferred stock, shares authorized	100,000	100,000
Cumulative convertible preferred stock, shares issued	0	0
Cumulative convertible preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	56,715,304	56,220,214
Common stock, shares outstanding	53,726,328	53,536,101
Treasury stock, shares	1,850,173	1,784,897