Goodwill and Other Intangible Assets (Intangible Assets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 214,810	$ 173,272
Accumulated Amortization	59,270	40,764
Net Carrying Amount	155,540	132,508
Indefinite-lived other intangible asset	4,738	4,168
Total other intangible assets	219,548	177,440
Other intangible assets, net of amortization	160,278	136,676
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	128,907	96,148
Accumulated Amortization	22,514	14,311
Net Carrying Amount	106,393	81,837
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	73,891	68,880
Accumulated Amortization	33,491	24,365
Net Carrying Amount	40,400	44,515
Trademarks and patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,213	6,825
Accumulated Amortization	2,157	1,156
Net Carrying Amount	8,056	5,669
Covenant not to compete
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,799	1,419
Accumulated Amortization	1,108	932
Net Carrying Amount	$ 691	$ 487