SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION BS (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Mar. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 139,341	$ 104,146	$ 263,910	$ 204,341
Accounts receivable	231,785	258,618
Inventories	145,731	147,169
Assets held for sale	41,242	57,827
Prepaid expenses and other current assets	75,906	70,091
Total current assets	634,005	637,851
Intercompany investment	0	0
Investment in unconsolidated affiliates	196,350	216,376
Intercompany notes receivable	0	0
Property and equipment, at cost	2,682,730	2,665,828
Less - Accumulated depreciation and amortization	(527,140)	(508,727)
Property, plant and equipment, net	2,155,590	2,157,101
Goodwill	52,404	75,628
Other assets	162,703	143,764
Total assets	3,201,052	3,230,720
Current liabilities:
Accounts payable	108,678	84,193
Accrued liabilities	227,302	258,445
Current deferred taxes	15,108	17,704
Short-term borrowings and current maturities of long-term debt	30,041	18,730
Deferred sale leaseback	0	55,934
Total current liabilities	381,129	435,006
Long-term debt, less current maturities	973,339	845,692
Intercompany notes payable	0	0
Accrued pension liabilities	91,908	99,576
Other liabilities and deferred credits	26,942	39,782
Deferred taxes	150,172	165,655
Redeemable noncontrolling interests	30,527	26,223
Common stock	377	376
Additional paid-in-capital	788,672	781,837
Retained earnings	1,208,809	1,284,442
Accumulated other comprehensive income (loss)	(274,100)	(270,329)
Treasury shares	(184,796)	(184,796)
Total Bristow Group stockholders' investment	1,538,962	1,611,530
Noncontrolling interests	8,073	7,256
Total stockholders' investment	1,547,035	1,618,786
Total liabilities, redeemable noncontrolling interests and stockholders' investment	3,201,052	3,230,720
Parent Company
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	20,080	126	54,476	4,640
Accounts receivable	408,430	377,158
Inventories	8	0
Assets held for sale	0	0
Prepaid expenses and other current assets	4,686	4,850
Total current assets	433,204	382,134
Intercompany investment	1,196,923	1,410,347
Investment in unconsolidated affiliates	0	0
Intercompany notes receivable	1,279,069	1,184,335
Property and equipment, at cost	129,966	111,287
Less - Accumulated depreciation and amortization	(19,708)	(16,431)
Property, plant and equipment, net	110,258	94,856
Goodwill	0	0
Other assets	176,270	43,423
Total assets	3,195,724	3,115,095
Current liabilities:
Accounts payable	329,595	203,700
Accrued liabilities	20,210	31,805
Current deferred taxes	1,986	(3,661)
Short-term borrowings and current maturities of long-term debt	21,001	9,088
Deferred sale leaseback		0
Total current liabilities	372,792	240,932
Long-term debt, less current maturities	946,946	812,536
Intercompany notes payable	0	100,000
Accrued pension liabilities	0	0
Other liabilities and deferred credits	9,710	17,144
Deferred taxes	139,201	141,771
Redeemable noncontrolling interests	0	0
Common stock	377	376
Additional paid-in-capital	788,672	781,837
Retained earnings	1,208,809	1,284,442
Accumulated other comprehensive income (loss)	(87,475)	(80,604)
Treasury shares	(184,796)	(184,796)
Total Bristow Group stockholders' investment	1,725,587	1,801,255
Noncontrolling interests	1,488	1,457
Total stockholders' investment	1,727,075	1,802,712
Total liabilities, redeemable noncontrolling interests and stockholders' investment	3,195,724	3,115,095
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	1,153	884	13,768	0
Accounts receivable	490,607	342,239
Inventories	39,943	44,285
Assets held for sale	29,896	54,695
Prepaid expenses and other current assets	5,432	7,035
Total current assets	567,031	449,138
Intercompany investment	111,379	111,380
Investment in unconsolidated affiliates	0	0
Intercompany notes receivable	13,786	0
Property and equipment, at cost	1,126,657	1,165,164
Less - Accumulated depreciation and amortization	(228,681)	(223,245)
Property, plant and equipment, net	897,976	941,919
Goodwill	4,756	4,756
Other assets	893	988
Total assets	1,595,821	1,508,181
Current liabilities:
Accounts payable	536,606	369,854
Accrued liabilities	37,915	37,860
Current deferred taxes	1,922	2,503
Short-term borrowings and current maturities of long-term debt	0	0
Deferred sale leaseback		55,934
Total current liabilities	576,443	466,151
Long-term debt, less current maturities	0	0
Intercompany notes payable	116,846	131,075
Accrued pension liabilities	0	0
Other liabilities and deferred credits	7,443	8,379
Deferred taxes	5,380	6,346
Redeemable noncontrolling interests	0	0
Common stock	4,996	4,996
Additional paid-in-capital	9,291	9,291
Retained earnings	875,422	881,943
Accumulated other comprehensive income (loss)	0	0
Treasury shares	0	0
Total Bristow Group stockholders' investment	889,709	896,230
Noncontrolling interests	0	0
Total stockholders' investment	889,709	896,230
Total liabilities, redeemable noncontrolling interests and stockholders' investment	1,595,821	1,508,181
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	118,108	103,136	195,666	200,147
Accounts receivable	371,400	447,776
Inventories	105,780	102,884
Assets held for sale	11,346	3,132
Prepaid expenses and other current assets	65,788	58,206
Total current assets	672,422	715,134
Intercompany investment	152,990	0
Investment in unconsolidated affiliates	196,350	216,376
Intercompany notes receivable	0	0
Property and equipment, at cost	1,426,107	1,389,377
Less - Accumulated depreciation and amortization	(278,751)	(269,051)
Property, plant and equipment, net	1,147,356	1,120,326
Goodwill	47,648	70,872
Other assets	90,532	99,353
Total assets	2,307,298	2,222,061
Current liabilities:
Accounts payable	347,618	289,838
Accrued liabilities	1,230,505	206,789
Current deferred taxes	11,200	18,862
Short-term borrowings and current maturities of long-term debt	9,040	9,642
Deferred sale leaseback		0
Total current liabilities	1,598,363	525,131
Long-term debt, less current maturities	26,393	33,156
Intercompany notes payable	154,663	1,065,918
Accrued pension liabilities	91,908	99,576
Other liabilities and deferred credits	9,789	21,711
Deferred taxes	5,591	17,538
Redeemable noncontrolling interests	30,527	26,223
Common stock	22,876	22,876
Additional paid-in-capital	284,048	284,048
Retained earnings	49,155	133,559
Accumulated other comprehensive income (loss)	27,400	(13,474)
Treasury shares	0	0
Total Bristow Group stockholders' investment	383,479	427,009
Noncontrolling interests	6,585	5,799
Total stockholders' investment	390,064	432,808
Total liabilities, redeemable noncontrolling interests and stockholders' investment	2,307,298	2,222,061
Consolidations, Eliminations
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0	$ 0	$ (446)
Accounts receivable	(1,038,652)	(908,555)
Inventories	0	0
Assets held for sale	0	0
Prepaid expenses and other current assets	0	0
Total current assets	(1,038,652)	(908,555)
Intercompany investment	(1,461,292)	(1,521,727)
Investment in unconsolidated affiliates	0	0
Intercompany notes receivable	(1,292,855)	(1,184,335)
Property and equipment, at cost	0	0
Less - Accumulated depreciation and amortization	0	0
Property, plant and equipment, net	0	0
Goodwill	0	0
Other assets	(104,992)	0
Total assets	(3,897,791)	(3,614,617)
Current liabilities:
Accounts payable	(1,105,141)	(779,199)
Accrued liabilities	(1,061,328)	(18,009)
Current deferred taxes	0	0
Short-term borrowings and current maturities of long-term debt	0	0
Deferred sale leaseback		0
Total current liabilities	(2,166,469)	(797,208)
Long-term debt, less current maturities	0	0
Intercompany notes payable	(271,509)	(1,296,993)
Accrued pension liabilities	0	0
Other liabilities and deferred credits	0	(7,452)
Deferred taxes	0	0
Redeemable noncontrolling interests	0	0
Common stock	(27,872)	(27,872)
Additional paid-in-capital	(293,339)	(293,339)
Retained earnings	(924,577)	(1,015,502)
Accumulated other comprehensive income (loss)	(214,025)	(176,251)
Treasury shares	0	0
Total Bristow Group stockholders' investment	(1,459,813)	(1,512,964)
Noncontrolling interests	0	0
Total stockholders' investment	(1,459,813)	(1,512,964)
Total liabilities, redeemable noncontrolling interests and stockholders' investment	(3,897,791)	(3,614,617)
Land and Building
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	237,704	171,959
Land and Building | Parent Company
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	4,539	2,830
Land and Building | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	60,858	50,946
Land and Building | Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	172,307	118,183
Land and Building | Consolidations, Eliminations
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	0	0
Aircraft And Equipment
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	2,445,026	2,493,869
Aircraft And Equipment | Parent Company
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	125,427	108,457
Aircraft And Equipment | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	1,065,799	1,114,218
Aircraft And Equipment | Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	1,253,800	1,271,194
Aircraft And Equipment | Consolidations, Eliminations
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	$ 0	$ 0