Goodwill and Intangible Assets - Classes of Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Total cost of intangibles	$ 156,424	$ 159,887
Accumulated Amortization	27,340	19,858
Finite-lived intangibles, net	115,637
Intangible assets, net	129,084	140,029
Trade Name
Finite-Lived Intangible Assets [Line Items]
Trade Name - Indefinite-lived	13,447	14,559
Trade Name
Finite-Lived Intangible Assets [Line Items]
Cost	3,679	3,675
Accumulated Amortization	3,552	3,042
Finite-lived intangibles, net	$ 127	$ 633
Non-Compete Agreement
Finite-Lived Intangible Assets [Line Items]
Amortization Period	24 months	24 months
Cost	$ 27	$ 27
Accumulated Amortization	27	18
Finite-lived intangibles, net	$ 0	$ 9
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Amortization Period	180 months	180 months
Cost	$ 139,271	$ 141,626
Accumulated Amortization	23,761	16,798
Finite-lived intangibles, net	$ 115,510	$ 124,828
Minimum | Trade Name
Finite-Lived Intangible Assets [Line Items]
Amortization Period	12 months	12 months
Maximum | Trade Name
Finite-Lived Intangible Assets [Line Items]
Amortization Period	24 months	24 months