Commitments and Contingencies - Future Minimum Lease Payments under Non-Cancellable Operating Leases and Future Minimum Sublease Receipts (Detail) $ in Thousands	Dec. 31, 2018 USD ($)
Future Minimum Lease Payments
2019	$ 6,559
2020	6,216
2021	4,355
2022	2,582
2023	1,423
Thereafter	24,180
Total	45,315
Future Minimum Sublease Receipts
2019	351
2020	60
2021	0
2022	0
2023	0
Thereafter	0
Total	$ 411