Segment Reporting - Information about Operations in Different Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Revenues	$ 1,046,537	$ 476,083	$ 1,597,000	$ 1,079,894
Operating income (loss)	41,632	31,525	48,197	(6,684)
Capital expenditures	24,013	117,064	47,985	154,957
Depreciation and amortization	26,044	21,645	51,371	46,247
Drydock amortization	4,386	3,020	9,658	9,966
AEA [Member]
Segment Reporting Information [Line Items]
Revenues	104,701	125,865	248,014	307,551
Operating income (loss)	4,588	6,410	19,659	(30,002)
Capital expenditures	516	32,944	3,429	40,353
Depreciation and amortization	10,464	4,560	23,287	15,387
Drydock amortization	3,161	983	6,244	5,545
MEA [Member]
Segment Reporting Information [Line Items]
Revenues	420,221	236,236	574,021	496,536
Operating income (loss)	30,794	19,667	35,971	16,933
Capital expenditures	4,828	6,810	14,942	29,385
Depreciation and amortization	9,019	9,328	14,757	17,497
Drydock amortization	550	468	1,163	897
ASA [Member]
Segment Reporting Information [Line Items]
Revenues	521,615	113,982	774,965	275,807
Operating income (loss)	11,303	5,779	(1,613)	9,210
Capital expenditures	18,669	74,229	29,493	78,297
Depreciation and amortization	3,862	6,079	7,778	9,987
Drydock amortization	675	1,569	2,251	3,524
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(5,053)	(331)	(5,820)	(2,825)
Capital expenditures		3,081	121	6,922
Depreciation and amortization	$ 2,699	$ 1,678	$ 5,549	$ 3,376