XML 40 R29.htm IDEA: XBRL DOCUMENT v3.21.1
Share-based Compensation (Summary of Restricted Stock Activity) (Detail) - Restricted Stock [Member] - $ / shares
shares in Thousands
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Shares    
Outstanding at beginning of period 50 46
Granted 17 29
Vested (14) (21)
Forfeited   (3)
Outstanding at end of period 53 51
Weighted-Average Grant Date Fair Value    
Outstanding at beginning of period $ 116.06 $ 98.28
Granted 253.03 100.68
Vested 109.14 66.73
Forfeited   105.29
Outstanding at end of period $ 157.80 $ 112.43