Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 1,676	$ 1,190
Preferred stock, at par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	100,000	100,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	80,000,000	80,000,000
Common stock, shares issued (in shares)	62,955,872	62,162,875
Common stock, shares outstanding (in shares)	57,688,578	57,342,279
Treasury stock, shares (in shares)	3,947,982	3,770,224