CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Total revenue	$ 585,301	$ 469,129	$ 1,079,271	$ 914,892
Costs and expenses:
Selling, general and administrative	120,531	93,820	223,903	184,729
Amortization of intangible assets	18,740	9,819	29,008	20,556
Operating income	76,710	81,686	144,539	151,392
Other income (expense):
Interest income	182	161	464	363
Interest expense	(18,643)	(7,403)	(29,834)	(14,386)
Other income, net	12,039	2,472	18,159	17,594
Income from continuing operations, before income taxes	70,288	76,916	133,328	154,963
Provision for income taxes	17,438	22,243	27,210	53,327
Income from continuing operations, net of income taxes	52,850	54,673	106,118	101,636
Income (loss) from discontinued operations, net of income taxes	1,529	(71)	1,506	(75)
Net income	54,379	54,602	107,624	101,561
Less: Net income attributable to noncontrolling interests	670	650	1,284	831
Net income attributable to common shareholders	$ 53,709	$ 53,952	$ 106,340	$ 100,730
Basic:
Continuing operations attributable to common shareholders (in dollars per share)	$ 1.08	$ 1.14	$ 2.18	$ 2.12
Discontinued operations (in dollars per share)	0.03	0.00	0.03	0.00
Net income attributable to common shareholders (in dollars per share)	1.11	1.13	2.22	2.12
Diluted:
Continuing operations attributable to common shareholders (in dollars per share)	1.06	1.12	2.14	2.08
Discontinued operations (in dollars per share)	0.03	0.00	0.03	0.00
Net income attributable to common shareholders (in dollars per share)	$ 1.10	$ 1.12	$ 2.17	$ 2.08
Service
Total revenue	$ 438,456	$ 329,398	$ 783,910	$ 633,929
Costs and expenses:
Cost of services provided (excluding amortization of intangible assets)	302,304	215,053	546,112	422,220
Product
Total revenue	146,845	139,731	295,361	280,963
Costs and expenses:
Cost of services provided (excluding amortization of intangible assets)	$ 67,016	$ 68,751	$ 135,709	$ 135,995