Segment Reporting - Information about Operations in Different Segments (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenues	[1]	$ 706,627	$ 1,046,537	$ 1,435,659	$ 1,597,000
Operating income (loss)	[2]	56,988	49,113	92,981	62,419
Capital expenditures	[3]	138,774	24,013	170,674	47,985
Depreciation and amortization		21,395	26,044	41,997	51,371
Drydock amortization		2,992	4,386	6,932	9,658
Operating Segments [Member] | AEA [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	86,810	104,701	149,435	248,014
Operating income (loss)	[2]	3,168	6,176	(21,753)	22,433
Capital expenditures	[3]	941	516	3,526	3,429
Depreciation and amortization		7,172	10,464	14,315	23,287
Drydock amortization		2,234	3,161	5,410	6,244
Operating Segments [Member] | MEA [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	317,834	420,221	588,089	574,021
Operating income (loss)	[2]	41,959	30,823	80,426	36,065
Capital expenditures	[3]	2,469	4,828	4,703	14,942
Depreciation and amortization		6,033	9,019	10,844	14,757
Drydock amortization		529	550	1,064	1,163
Operating Segments [Member] | ASA [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	301,983	521,615	698,135	774,965
Operating income (loss)	[2]	12,274	17,157	37,407	9,731
Capital expenditures	[3]	134,567	18,669	161,575	29,493
Depreciation and amortization		6,060	3,862	12,449	7,778
Drydock amortization		229	675	458	2,251
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	[2]	(413)	(5,043)	(3,099)	(5,810)
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Capital expenditures	[3]	797		870	121
Depreciation and amortization		$ 2,130	$ 2,699	$ 4,389	$ 5,549

[1] Intersegment transactions included in revenues were not significant for either of the periods presented.

[2] The AEA segment’s operating results for the six months ended June 30, 2016 include an impairment charge of $32 million related to the Agile vessel. The ASA segment’s operating results in the six months ended June 30, 2015 included a $4 million impairment charge for the DB 101 and $3 million of loss on disposal of this asset.

[3] Total capital expenditures represent expenditures for which cash payments were made during the period. Capital expenditures for the three months ended June 30, 2016 included $1 million of cash payments for liabilities outstanding as of March 31, 2016 and for the six months ended June 30, 2016 excluded $2 million in accrued liabilities outstanding at the end of the period. Capital expenditures for the three and six months ended June 30, 2015 included $8 million and $11 million, respectively, of cash payments for accrued capital expenditures outstanding at the end of the respective periods.