XML 65 R50.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation - Deferred Stock Unit, Performance-Based Stock Unit and Restricted Stock Activity (Detail) - Restricted Stock Unit And Performance Stock Unit And Deferred Stock Unit [Member] - $ / shares
shares in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Unvested, shares    
Unvested, Beginning Balance 933 670
Granted 217 413
Vested (135) (89)
Forfeited (10) (61)
Unvested, Ending Balance 1,005 933
Weighted Average Grant Date Fair Value    
Unvested, Beginning Balance $ 14.79 $ 16.16
Granted 11,430.00 13.27
Vested 13,750.00 16.46
Forfeited 14,380.00 17.08
Unvested ,Ending Balance $ 14,210.00 $ 14.79