Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowances	$ 5,279	$ 4,796
Preferred stock, shares, issued (in shares)	0	0
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares, authorized (in shares)	5,000,000	5,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares, authorized (in shares)	100,000,000	100,000,000
Common Stock, shares, issued (in shares)	47,064,000	45,778,000
Common stock, shares, outstanding (in shares)	37,919,000	36,633,000
Treasury stock, shares (in shares)	9,145,000	9,145,000