Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation Plans - Outstanding Awards Under 2013 Omnibus Equity Incentive Plan (Detail)

v3.19.3
Stock-Based Compensation Plans - Outstanding Awards Under 2013 Omnibus Equity Incentive Plan (Detail)
$ / shares in Units, $ in Thousands
9 Months Ended
Sep. 30, 2019
USD ($)
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Nonvested shares at December 31, 2018 891,575
Granted 331,380
Vested (388,898)
Transferred 0
Forfeited/canceled (40,473)
Nonvested shares at September 30, 2019 793,584
Unrecognized stock-based compensation expense as of September 30, 2019 | $ $ 23,499
Weighted average remaining vesting period (years) as of September 30, 2019 3 years 6 months 21 days
Nonvested weighted average grant date fair value per share, beginning balance | $ / shares $ 27.59
Weighted average grant date fair value per share, Granted | $ / shares 38.62
Weighted average grant date fair value, Vested | $ / shares 24.11
Weighted average grant date fair value, Transferred | $ / shares 29.68
Weighted average grant date fair value, Forfeited/canceled | $ / shares 30.99
Nonvested weighted average grant date fair value per share, ending balance | $ / shares $ 33.73
Restricted Stock Awards [Member] | Non-Employee Directors [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Nonvested shares at December 31, 2018 27,096
Granted 12,806
Vested (22,422)
Transferred 0
Forfeited/canceled 0
Nonvested shares at September 30, 2019 17,480
Unrecognized stock-based compensation expense as of September 30, 2019 | $ $ 397
Weighted average remaining vesting period (years) as of September 30, 2019 7 months 17 days
Restricted Stock Units [Member] | Employees [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Nonvested shares at December 31, 2018 471,782
Granted 241,932
Vested (182,714)
Transferred (8,136)
Forfeited/canceled (8,119)
Nonvested shares at September 30, 2019 514,745
Unrecognized stock-based compensation expense as of September 30, 2019 | $ $ 14,629
Weighted average remaining vesting period (years) as of September 30, 2019 3 years 8 months 12 days
Restricted Stock Units [Member] | Independent Contractors, Prior to Adoption of New Standard [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Nonvested shares at December 31, 2018 392,697
Granted 76,642
Vested (183,762)
Transferred 8,136
Forfeited/canceled (32,354)
Nonvested shares at September 30, 2019 261,359
Unrecognized stock-based compensation expense as of September 30, 2019 | $ $ 8,473
Weighted average remaining vesting period (years) as of September 30, 2019 3 years 5 months 12 days