Restructuring - Restructuring Costs Incurred and Future Cost Expected to be Incurred (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period	$ 0	$ 6,367,000
Incurred from inception to March 31, 2017	99,321,000
Americas Restructuring [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred from inception to March 31, 2017	44,194,000
McDermott Profitability Initiative [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period		1,501,000
Incurred from inception to March 31, 2017	46,962,000
McDermott Profitability Initiative [Member] | Severance and other personnel-related costs [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period		433,000
Incurred from inception to March 31, 2017	17,807,000
McDermott Profitability Initiative [Member] | Asset impairment and disposal [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred from inception to March 31, 2017	7,471,000
McDermott Profitability Initiative [Member] | Legal and other advisor fees [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period		173,000
Incurred from inception to March 31, 2017	11,639,000
McDermott Profitability Initiative [Member] | Other Charges
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period		895,000
Incurred from inception to March 31, 2017	10,045,000
Additional Overhead Reduction [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period		4,866,000
Incurred from inception to March 31, 2017	8,165,000
Additional Overhead Reduction [Member] | Severance and other personnel-related costs [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period		2,971,000
Incurred from inception to March 31, 2017	5,012,000
Additional Overhead Reduction [Member] | Legal and other advisor fees [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period		1,728,000
Incurred from inception to March 31, 2017	2,768,000
Additional Overhead Reduction [Member] | Other Charges
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Incurred for the period		$ 167,000
Incurred from inception to March 31, 2017	$ 385,000