Goodwill and Intangibles - Intangible Assets and Accumulated Amortization Balances (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 200,235	$ 206,113
Accumulated Amortization	(132,556)	(121,744)
Net Carrying Amount	67,679	84,369
Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	155,409	156,557
Accumulated Amortization	(122,657)	(113,871)
Net Carrying Amount	32,752	42,686
Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	44,826	49,556
Accumulated Amortization	(9,899)	(7,873)
Net Carrying Amount	$ 34,927	$ 41,683