XML 100 R83.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock-based Compensation by Payment Award (Details)
12 Months Ended
Dec. 31, 2018
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Non-vested, share, beginning 536,750
Granted (shares) 241,988
Vested (shares) (218,625)
Forfeited (shares) (18,555)
Non-vested, share, end 541,558
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant [Roll Forward]  
Nonvested, weighted average grant date fair value, beginning (USD per share) | $ / shares $ 105.42
Grants in period, weighted average grant date fair value (USD per share) | $ / shares 100.12
Vested in period, weighted average grant date fair value (USD per share) | $ / shares 103.61
Forfeited in period, weighted average grant date fair value (USD per share) | $ / shares 108.20
Nonvested, weighted average grant date fair value, end (USD per share) | $ / shares $ 103.68
Restricted Stock Units (RSUs) [Member] | Total Restricted Stock Award [Member] | Director Stock Award Program [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of shares to be issued upon vesting 19,002
Number of shares available for future grant 537,086