XML 101 R89.htm IDEA: XBRL DOCUMENT v3.21.1
Summary of Status of Restricted Stock Units and Changes (Detail) - Restricted Stock Units - $ / shares
shares in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Number of Nonvested Stock Units        
Nonvested at beginning period 1,643 1,621 1,538  
Restricted stock units granted 1,692 1,584 1,622  
Restricted stock units vested (1,564) (1,505) (1,517)  
Restricted stock units forfeited (57) (57) (22)  
Nonvested at ending period 1,714 1,643 1,621 1,538
Weighted Average Grant Date Fair Value        
Nonvested at beginning period $ 8.08 $ 13.85 $ 10.36  
Restricted stock units granted 9.40 8.01 13.86  
Restricted stock units vested 8.02 14.12 9.79  
Restricted stock units forfeited 9.31 9.59 11.75  
Nonvested at ending period $ 9.37 $ 8.08 $ 13.85 $ 10.36
Weighted Average Remaining Recognition Period (Years)        
Nonvested at ending period 3 months 21 days 3 months 14 days 4 months 17 days 3 months 29 days