Commitments and Contingencies - Future Minimum Payments for all Operating Lease Obligations and Sublease Rental Income (Detail) $ in Thousands	Dec. 31, 2018 USD ($)
Operating Leases
2019	$ 49,757
2020	47,084
2021	44,480
2022	24,471
2023	20,309
Thereafter	75,190
Total	261,291
Sublease Rental Income
2019	4,760
2020	3,944
2021	3,864
2022	707
2023	614
Thereafter	939
Total	$ 14,828