Acquisitions and Dispositions - Summary of Purchase Price Allocation Including Finalization of Asset Valuations (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 396,829	$ 281,708
MEGTEC Holdings Inc [Member]
Business Acquisition [Line Items]
Unrestricted cash	14,232
Accounts receivable	23,459
Inventories	5,528
Other current assets	9,069
Property, plant and equipment	5,090
Goodwill	115,314
Intangible assets	42,000
Total assets acquired	214,692
Accounts payable	13,402
Advance billings on contracts	9,144
Other current liabilities	17,477
Pension liability	5,041
Deferred income taxes	12,137
Other liabilities	1,085
Total liabilities assumed	58,286
Net assets acquired	156,406
Net assets acquired	156,406
Unrestricted cash acquired	14,232
Net assets acquired, net of unrestricted cash acquired	142,174
Amount of tax deductible goodwill