Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Allowance for Doubtful Accounts	$ 672	$ 669
Stockholders' equity:
Preferred stock, shares authorized (in shares)	2,000	2,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value per share (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	120,000	120,000
Common stock, shares issued (in shares)	79,853	78,267
Common stock, shares, outstanding (in shares)	75,443	74,009
Treasury stock, shares (in shares)	4,410	4,258