Goodwill and Other Intangible Assets (Intangible Assets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 244,647	$ 214,810
Accumulated Amortization	72,164	59,270
Net Carrying Amount	172,483	155,540
Indefinite-lived other intangible asset	4,525	4,738
Total other intangible assets	249,172	219,548
Other intangible assets, net of amortization	177,008	160,278
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	149,753	128,907
Accumulated Amortization	30,078	22,514
Net Carrying Amount	119,675	106,393
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	81,535	73,891
Accumulated Amortization	38,624	33,491
Net Carrying Amount	42,911	40,400
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	12,019	10,213
Accumulated Amortization	3,213	2,157
Net Carrying Amount	8,806	8,056
Covenants not to compete
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,340	1,799
Accumulated Amortization	249	1,108
Net Carrying Amount	$ 1,091	$ 691