Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Allowance for Doubtful Accounts	$ 669	$ 704
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)	78,267	63,384
Common stock, shares, outstanding (in shares)	74,009	59,203
Treasury stock, shares (in shares)	4,258	4,181