Allocation of Acquisition Costs to Assets Acquired and Liabilities Assumed (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 28, 2014	Mar. 18, 2013	Apr. 30, 2012	Apr. 11, 2012	Jul. 20, 2012
Business Acquisition [Line Items]
Goodwill	$ 1,321,277	$ 1,349,456	$ 1,321,727
Aegis Flow Technologies [Member]
Business Acquisition [Line Items]
Accounts receivable				1,147
Inventory				6,230
Other current assets, net of cash acquired				232
Property, plant and equipment				2,988
Goodwill				7,711
Intangible assets				8,770
Total assets acquired				27,078
Total liabilities assumed				(1,633)
Net assets acquired				25,445
FTL
Business Acquisition [Line Items]
Accounts receivable					3,454
Inventory					4,524
Other current assets, net of cash acquired					131
Property, plant and equipment					1,357
Goodwill					17,994
Intangible assets					13,016
Total assets acquired					40,476
Total liabilities assumed					(5,939)
Net assets acquired					34,537
ERC
Business Acquisition [Line Items]
Accounts receivable			5,766
Inventory			4,224
Other current assets, net of cash acquired			981
Property, plant and equipment			2,738
Goodwill			8,499			8,500
Intangible assets			5,642
Other assets			1,509
Total assets acquired			29,359
Total liabilities assumed			(16,074)
Net assets acquired			13,285
PPC
Business Acquisition [Line Items]
Accounts receivable			877
Inventory			932
Other current assets, net of cash acquired			252
Property, plant and equipment			1,936
Goodwill			13,941				13,900
Intangible assets			5,104
Other assets			13
Total assets acquired			23,055
Total liabilities assumed			(2,465)
Net assets acquired			20,590
Matcon
Business Acquisition [Line Items]
Accounts receivable			7,768
Inventory			604
Other current assets, net of cash acquired			1,880
Property, plant and equipment			5,695
Goodwill			27,947					28,000
Intangible assets			14,081
Other assets			53
Total assets acquired			58,028
Total liabilities assumed			(12,215)
Net assets acquired			45,813
ERC, PPC and Matcon [Member]
Business Acquisition [Line Items]
Accounts receivable			14,411
Inventory			5,760
Other current assets, net of cash acquired			3,113
Property, plant and equipment			10,369
Goodwill			50,387
Intangible assets			24,827
Other assets			1,575
Total assets acquired			110,442
Total liabilities assumed			(30,754)
Net assets acquired			$ 79,688