Quarterly report pursuant to Section 13 or 15(d)

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

v2.4.0.8
Share-Based Payments Share-Based Payments - Employee Stock Purchase Plan (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]    
Share-based compensation $ 4,619 $ 4,550
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) 416,881  
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 2  
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares) 4,241 4,121
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased (in dollars per share) $ 32.34 $ 29.04
Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) $ 5.94 $ 3.23
Share-based compensation $ 26 $ 13