Identifiable Intangible Assets from Acquisitions - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets from acquisitions	$ 1,568	$ 3,136
Estimated remaining amortization expense in 2019	3,100	3,100
Estimated amortization expense in 2020	5,700	5,700
Estimated amortization expense in 2021	4,200	4,200
Estimated amortization expense in 2022	2,500	2,500
Estimated amortization expense in 2023	$ 2,100	$ 2,100
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Weighted average useful life		5 years
Technologies
Finite Lived Intangible Assets [Line Items]
Weighted average useful life		3 years
Tradenames
Finite Lived Intangible Assets [Line Items]
Weighted average useful life		2 years
Non-compete Agreements | Minimum
Finite Lived Intangible Assets [Line Items]
Weighted average useful life		1 year
Non-compete Agreements | Maximum
Finite Lived Intangible Assets [Line Items]
Weighted average useful life		2 years