Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Narrative) (Details)

v3.5.0.2
Stockholders' Equity (Narrative) (Details) - USD ($)
$ / shares in Units, $ in Millions
6 Months Ended
Jan. 08, 2016
Jun. 30, 2016
Jun. 30, 2015
Stock Options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Net proceeds from employee stock purchase plan   $ 2.4 $ 5.3
2002 Stock Incentive Plan | Stock Options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares available for future option grants   948,729  
Employee Stock Purchase Plan      
Employee Stock Purchase Plan      
Shares allowed to purchase in employee stock purchase plan   1,250  
Shares issued in period   1,241 0
Shares available for future purchases   71,126  
OMT, Inc.      
Employee Stock Purchase Plan      
Common stock issued in acquisition (shares) 790,163    
20-day volume-weighted average price of common stock issued in acquisition (usd per share) $ 107.66