Quarterly report pursuant to Section 13 or 15(d)

Share-Based Payments Share-Based Payments - Employee Stock Purchase Plan (Details)

v3.5.0.2
Share-Based Payments Share-Based Payments - Employee Stock Purchase Plan (Details)
$ / shares in Units, $ in Thousands
 6 Months Ended
Jun. 30, 2016
USD ($)
Days
$ / shares
shares
Jun. 30, 2015
USD ($)
$ / shares
shares
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]    
Share-based compensation | $ $ 4,111 $ 3,676
Employee Stock Purchase Plan [Member]    
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | shares 387,395  
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date 90.00%  
Number of Large Lump Sum Contributions Related to ESPP Stock Purchases | Days 2  
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares) | shares 5,592 5,087
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased (in dollars per share) | $ / shares $ 38.50 $ 44.74
Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares $ 6.03 $ 7.52
Share-based compensation | $ $ 34 $ 37