Detail of Certain Balance Sheet Accounts - Contracts in Progress (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Costs incurred on contracts in progress	$ 6,687,484	$ 5,725,078
Estimated earnings, net of estimated losses	766,560	756,974
Cost and estimated earnings, total	7,454,044	6,482,052
Less - Billings to date	(7,255,582)	(6,563,537)
Cost and estimated earnings, Net	198,462	(81,485)
Costs and estimated earnings in excess of billings on uncompleted contracts	473,308	317,745
Less - Billings in excess of costs and estimated earnings on uncompleted contracts	(274,846)	(399,230)
Cost and estimated earnings, Net	$ 198,462	$ (81,485)

Liability attributable to (i) billings in excess of costs under the percentage of completion contract accounting method representing the difference between contractually invoiced amounts (billings) and revenue recognized based, for example, on costs incurred to estimated total costs at period end or (ii) contractually invoiced amounts (billings) in excess of costs incurred and accumulated under the completed contract accounting method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 35
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=68068069&loc=d3e57807-111642

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 35
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=68068069&loc=d3e57788-111642

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 35
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68068069&loc=d3e57795-111642

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant