Operating Segments - Reconciliation of Total Reportable Segments' Revenues and EBITDA to Consolidated Revenues and Consolidated Income from Continuing Operations Before Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Revenues	$ 668,639	$ 610,633	$ 1,274,204	$ 1,162,014
Amortization of intangibles	(25,039)	(27,113)	(49,457)	(50,782)
Severance, restructuring, and acquisition integration costs	(24,928)	(9,560)	(45,322)	(16,160)
Depreciation expense	(12,000)	(11,500)	(23,900)	(22,900)
Operating income	56,506	62,776	100,709	114,373
Interest expense, net	(15,088)	(23,533)	(32,066)	(47,039)
Non-operating pension costs	(257)	(295)	(532)	(555)
Loss on debt extinguishment	(3,030)	(847)	(22,990)	(847)
Income before taxes	38,131	38,101	45,121	65,932
Reportable Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues	671,441	610,633	1,278,864	1,162,014
Deferred revenue adjustments	(2,802)	0	(4,660)	0
Consolidated Revenues	668,639	610,633	1,274,204	1,162,014
Total Segment EBITDA	123,506	110,522	227,384	203,892
Amortization of intangibles	(25,039)	(27,113)	(49,457)	(50,782)
Severance, restructuring, and acquisition integration costs	(24,928)	(9,560)	(45,322)	(16,160)
Depreciation expense	(12,026)	(11,528)	(23,891)	(22,911)
Purchase accounting effects related to acquisitions	(1,036)	(1,167)	(1,538)	(1,167)
Amortization of software development intangible assets	(488)	0	(724)	0
Loss on sale of assets	0	0	(94)	0
Income from equity method investment	0	2,277	0	3,284
Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income	$ (681)	$ (655)	$ (989)	$ (1,783)