The Company - Summary of Reconciliation of Beginning and Ending Restructuring Liability (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Restructuring Cost And Reserve [Line Items]
Balance, beginning of period
Additions, charged to costs	$ 14,772
Payments	(12,225)
Balance, end of period	2,547
One-Time Employee Termination Benefit Costs
Restructuring Cost And Reserve [Line Items]
Balance, beginning of period
Additions, charged to costs	8,449
Payments	(6,370)
Balance, end of period	2,079
Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Balance, beginning of period
Additions, charged to costs	660
Payments	(271)
Balance, end of period	389
Consulting Costs
Restructuring Cost And Reserve [Line Items]
Balance, beginning of period
Additions, charged to costs	3,156
Payments	(3,077)
Balance, end of period	79
Asset Disposal Costs
Restructuring Cost And Reserve [Line Items]
Additions, charged to costs	2,507
Payments	$ (2,507)