Acquisitions and Divestitures - Allocation of Acquisition Costs to Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Aug. 31, 2016	Jul. 01, 2016	Mar. 16, 2016	Dec. 31, 2015	Jul. 01, 2015	Jun. 10, 2015	May 29, 2015
Business Acquisition [Line Items]
Accounts receivable			$ 29,580
Inventory			61,562
Other current assets, net of cash acquired			5,512
Property, plant and equipment			23,427
Goodwill	$ 1,704,158	$ 1,632,592	287,996			$ 1,396,529
Intangible assets			217,677
Deferred income taxes			3,928
Total assets acquired			629,682
Current liabilities			(23,902)
Deferred income taxes			(72,607)
Other noncurrent liabilities			(23,172)
Net assets acquired			510,001
Akron Brass
Business Acquisition [Line Items]
Accounts receivable					$ 14,523
Inventory					29,157
Other current assets, net of cash acquired					446
Property, plant and equipment					12,195
Goodwill					124,643
Intangible assets					90,400
Deferred income taxes					0
Total assets acquired					271,364
Current liabilities					(7,081)
Deferred income taxes					(36,439)
Other noncurrent liabilities					(6,445)
Net assets acquired					$ 221,399
AWG Fittings
Business Acquisition [Line Items]
Accounts receivable				$ 5,867
Inventory				11,766
Other current assets, net of cash acquired				565
Property, plant and equipment				6,595
Goodwill				22,055
Intangible assets				10,279
Deferred income taxes				3,928
Total assets acquired				61,055
Current liabilities				(5,117)
Deferred income taxes				0
Other noncurrent liabilities				(8,444)
Net assets acquired				$ 47,494
SFC-Koenig
Business Acquisition [Line Items]
Accounts receivable			9,190
Inventory			20,639
Other current assets, net of cash acquired			4,501
Property, plant and equipment			4,637
Goodwill			141,298
Intangible assets			116,998
Deferred income taxes			0
Total assets acquired			297,263
Current liabilities			(11,704)
Deferred income taxes			(36,168)
Other noncurrent liabilities			(8,283)
Net assets acquired			$ 241,108
Novotema
Business Acquisition [Line Items]
Accounts receivable									$ 8,029
Inventory									2,886
Other current assets, net of cash acquired									1,866
Property, plant and equipment									11,844
Goodwill									34,316
Intangible assets									20,011
Total assets acquired									78,952
Current liabilities									(7,760)
Deferred income taxes									(7,803)
Other noncurrent liabilities									(2,291)
Net assets acquired									$ 61,098
Alfa Valvole
Business Acquisition [Line Items]
Accounts receivable								$ 13,487
Inventory								11,036
Other current assets, net of cash acquired								3,367
Property, plant and equipment								8,395
Goodwill								69,568
Intangible assets								32,058
Total assets acquired								137,911
Current liabilities								(11,279)
Deferred income taxes								(12,622)
Other noncurrent liabilities								(1,420)
Net assets acquired								$ 112,590
CPS
Business Acquisition [Line Items]
Accounts receivable							$ 945
Inventory							442
Other current assets, net of cash acquired							79
Property, plant and equipment							1,105
Goodwill							9,739
Intangible assets							12,290
Total assets acquired							24,600
Current liabilities							(420)
Deferred income taxes							0
Other noncurrent liabilities							0
Net assets acquired							$ 24,180
Other
Business Acquisition [Line Items]
Accounts receivable						0
Inventory						1,102
Other current assets, net of cash acquired						0
Property, plant and equipment						0
Goodwill						748
Intangible assets						0
Total assets acquired						1,850
Current liabilities						0
Deferred income taxes						0
Other noncurrent liabilities						0
Net assets acquired						1,850
Acquisitions in 2015
Business Acquisition [Line Items]
Accounts receivable						22,461
Inventory						15,466
Other current assets, net of cash acquired						5,312
Property, plant and equipment						21,344
Goodwill						114,371
Intangible assets						64,359
Total assets acquired						243,313
Current liabilities						(19,459)
Deferred income taxes						(20,425)
Other noncurrent liabilities						(3,711)
Net assets acquired						$ 199,718