Business Segment, Geographic Area, Product and Significant Customer Information - Reconciliation of Segment Gross Profit to Consolidated Net Income (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended
Apr. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Gross profit		$ 227,995	$ 168,385	$ 653,125	$ 382,211
Research and development		32,548	32,268	99,510	77,709
Selling, general and administrative		71,839	68,016	218,038	161,545
Acquisition and integration costs		2,466	2,641	4,698	25,190
Restructuring		10		2,596	24
Asset impairment				6,719
Amortization of intangible assets		10,977	12,452	34,946	22,990	$ 22,990
Income from operations		110,155	53,008	286,618	94,753
Gain on sale of business	$ 74,856			74,856
Interest and other (expense), net		(8,784)	(10,760)	(24,846)	(16,332)
Income before income taxes		101,371	42,248	336,628	78,421
Provision for income taxes		25,377	9,699	75,134	19,099
Net income		75,994	32,549	261,494	59,322
Vacuum & Analysis [Member]
Segment Reporting Information [Line Items]
Gross profit		141,438	104,232	410,228	273,004
Light & Motion [Member]
Segment Reporting Information [Line Items]
Gross profit		$ 86,557	$ 64,153	$ 242,897	$ 109,207

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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