Segment Reporting Information - Operations and Assets (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 28, 2018 USD ($)	Sep. 29, 2017 USD ($)	Sep. 28, 2018 USD ($) segment	Sep. 29, 2017 USD ($)	Dec. 29, 2017 USD ($)
Segment Reporting Information [Line Items]
Revenues	$ 415,936	$ 379,812	$ 1,246,854	$ 1,099,885
Number of reportable segments \| segment			3
Operating Earnings	114,779	101,435	$ 339,853	289,280
Total Assets	1,485,501		1,485,501		$ 1,390,617
Operating Segments \| Industrial
Segment Reporting Information [Line Items]
Revenues	195,855	178,461	581,510	509,719
Operating Earnings	70,572	61,790	206,727	177,121
Total Assets	633,922		633,922		572,436
Operating Segments \| Process
Segment Reporting Information [Line Items]
Revenues	84,556	73,656	249,650	217,084
Operating Earnings	17,862	12,088	52,629	38,969
Total Assets	349,071		349,071		345,572
Operating Segments \| Contractor
Segment Reporting Information [Line Items]
Revenues	135,525	127,695	415,694	373,082
Operating Earnings	32,739	33,471	102,532	93,249
Total Assets	300,712		300,712		255,615
Unallocated corporate
Segment Reporting Information [Line Items]
Operating Earnings	(6,394)	$ (5,914)	(22,035)	$ (20,059)
Total Assets	$ 201,796		$ 201,796		$ 216,994

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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