Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.2
Stock-Based Compensation Plans - Outstanding Awards Under 2013 Omnibus Equity Incentive Plan (Detail) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 6 Months Ended
May 31, 2019
Feb. 28, 2019
Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Nonvested shares at December 31, 2018     891,575
Granted 50,494 211,791 262,285
Vested     (347,641)
Transferred     0
Forfeited/canceled     (23,551)
Nonvested shares at June 30, 2019     782,668
Unrecognized stock-based compensation expense as of June 30, 2019     $ 23,899
Weighted average remaining vesting period (years) as of June 30, 2019     3 years 6 months 29 days
Nonvested weighted average grant date fair value per share, beginning balance     $ 27.59
Weighted average grant date fair value per share, Granted     40.07
Weighted average grant date fair value, Vested     23.00
Weighted average grant date fair value, Transferred     29.68
Weighted average grant date fair value, Forfeited/canceled     31.36
Nonvested weighted average grant date fair value per share, ending balance     $ 33.70
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 10,542 0 10,542
Vested     (22,422)
Transferred     0
Forfeited/canceled     0
Nonvested shares at June 30, 2019     15,216
Unrecognized stock-based compensation expense as of June 30, 2019     $ 477
Weighted average remaining vesting period (years) as of June 30, 2019     10 months 2 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 32,926 204,060 236,986
Vested     (177,154)
Transferred     (8,136)
Forfeited/canceled     (3,277)
Nonvested shares at June 30, 2019     520,201
Unrecognized stock-based compensation expense as of June 30, 2019     $ 15,847
Weighted average remaining vesting period (years) as of June 30, 2019     3 years 10 months 9 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 7,026 7,731 14,757
Vested     (148,065)
Transferred     8,136
Forfeited/canceled     (20,274)
Nonvested shares at June 30, 2019     247,251
Unrecognized stock-based compensation expense as of June 30, 2019     $ 7,575
Weighted average remaining vesting period (years) as of June 30, 2019     3 years 2 months 1 day