Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Stock Compensation Awards Activity Roll Forward (Details)

v3.8.0.1
Stock-Based Compensation Stock Compensation Awards Activity Roll Forward (Details) - Restricted Stock Unit and Restricted Stock Award [Member] - $ / shares
shares in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number 3,183 3,670
RSUs granted in period (shares) 1,514  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (1,763)  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period (488)  
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value $ 27.11