Quarterly report pursuant to Section 13 or 15(d)

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

v3.2.0.727
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, 2015
Feb. 28, 2015
Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock outstanding, beginning balance, Shares     1,207,009
Granted 22,464 25,567 48,031
Vested     (197,459)
Forfeited/canceled     (16,337)
Stock outstanding, ending balance, Shares     1,041,244
Unrecognized stock-based compensation expense as of June 30, 2015     $ 30,703
Weighted average remaining vesting period (years) as of June 30, 2015     3 years 8 months 19 days
Nonvested weighted average grant date fair value per share, beginning balance     $ 18.23
Weighted average grant date fair value per share, Granted     37.18
Weighted average grant date fair value, Vested     14.68
Weighted average grant date fair value, Transferred     14.54
Weighted average grant date fair value, Forfeited/canceled     20.00
Nonvested weighted average grant date fair value per share, ending balance     $ 19.41
Restricted Stock [Member] | Non-employee directors [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock outstanding, beginning balance, Shares     42,882
Granted 10,110   10,110
Vested     (7,626)
Stock outstanding, ending balance, Shares     45,366
Unrecognized stock-based compensation expense as of June 30, 2015     $ 725
Weighted average remaining vesting period (years) as of June 30, 2015     1 year 10 months 6 days
Restricted Stock Units (RSUs) [Member] | Employees [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock outstanding, beginning balance, Shares     516,437
Granted 8,142 15,847 23,989
Vested     (55,450)
Transferred     (6,877)
Forfeited/canceled     (6,997)
Stock outstanding, ending balance, Shares     471,102
Unrecognized stock-based compensation expense as of June 30, 2015     $ 9,649
Weighted average remaining vesting period (years) as of June 30, 2015     4 years 22 days
Restricted Stock Units (RSUs) [Member] | Independent Contractors [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock outstanding, beginning balance, Shares     647,690
Granted 4,212 9,720 13,932
Vested     (134,383)
Transferred     6,877
Forfeited/canceled     (9,340)
Stock outstanding, ending balance, Shares     524,776
Unrecognized stock-based compensation expense as of June 30, 2015     $ 20,329
Weighted average remaining vesting period (years) as of June 30, 2015     3 years 6 months 29 days