SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION BS (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Nov. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 71,159		$ 104,310	$ 131,908	$ 104,146
Accounts receivable	216,406		249,317
Inventories	124,358		142,503
Assets held for sale	37,635		43,783
Prepaid expenses and other current assets	52,148		53,183
Total current assets	501,706		593,096
Intercompany investment	0		0
Investment in unconsolidated affiliates	206,797		194,952
Intercompany notes receivable	0		0
Property and equipment, at cost	2,848,488		2,823,675
Less - Accumulated depreciation and amortization	(585,821)		(540,423)
Property, plant and equipment, net	2,262,667		2,283,252
Goodwill	18,793	$ 27,500	29,990
Other assets	141,146		161,655
Total assets	3,131,109		3,262,945
Current liabilities:
Accounts payable	79,902		96,966
Accrued liabilities	175,393		201,605
Current deferred taxes	0		1,881
Short-term borrowings and current maturities of long-term debt	271,461		60,394
Contingent consideration	7,137		29,522
Total current liabilities	533,893		390,368
Long-term debt, less current maturities	990,207		1,071,578
Intercompany notes payable	0		0
Accrued pension liabilities	49,291		70,107
Other liabilities and deferred credits	26,456		33,273
Deferred taxes	149,961		172,254
Redeemable noncontrolling interest	8,267		15,473
Common stock	378		377
Additional paid-in-capital	807,046		801,173
Retained earnings	1,072,411		1,172,273
Accumulated other comprehensive income (loss)	(326,941)		(289,819)
Treasury shares	(184,796)		(184,796)
Total Bristow Group stockholders' investment	1,368,098		1,499,208
Noncontrolling interests	4,936		10,684
Total stockholders' investment	1,373,034		1,509,892
Total liabilities, redeemable noncontrolling interests and stockholders' investment	3,131,109		3,262,945
Land and Building
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	231,021		253,098
Aircraft And Equipment
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	2,617,467		2,570,577
Consolidations, Eliminations
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	(2,947)		0	0	0
Accounts receivable	(1,417,401)		(1,247,016)
Inventories	0		0
Assets held for sale	0		0
Prepaid expenses and other current assets	0		0
Total current assets	(1,420,348)		(1,247,016)
Intercompany investment	(2,754,218)		(2,457,119)
Investment in unconsolidated affiliates	0		0
Intercompany notes receivable	(143,545)		(170,465)
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	0		0
Total assets	(4,318,111)		(3,874,600)
Current liabilities:
Accounts payable	(1,322,577)		(883,242)
Accrued liabilities	(16,654)		(257,683)
Current deferred taxes	0		0
Short-term borrowings and current maturities of long-term debt	0		0
Contingent consideration	0		0
Total current liabilities	(1,339,231)		(1,140,925)
Long-term debt, less current maturities	0		0
Intercompany notes payable	(225,864)		(190,374)
Accrued pension liabilities	0		0
Other liabilities and deferred credits	0		0
Deferred taxes	0		0
Redeemable noncontrolling interest	0		0
Common stock	(135,345)		(135,344)
Additional paid-in-capital	(313,435)		(293,339)
Retained earnings	(1,644,951)		(1,683,245)
Accumulated other comprehensive income (loss)	(659,285)		(431,373)
Treasury shares	0		0
Total Bristow Group stockholders' investment	(2,753,016)		(2,543,301)
Noncontrolling interests	0		0
Total stockholders' investment	(2,753,016)		(2,543,301)
Total liabilities, redeemable noncontrolling interests and stockholders' investment	(4,318,111)		(3,874,600)
Consolidations, Eliminations | Land and Building
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	0		0
Consolidations, Eliminations | Aircraft And Equipment
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	0		0
Parent Company
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	2,397		35,241	721	126
Accounts receivable	570,910		768,641
Inventories	0		0
Assets held for sale	0		0
Prepaid expenses and other current assets	2,565		5,048
Total current assets	575,872		808,930
Intercompany investment	2,524,982		2,207,516
Investment in unconsolidated affiliates	0		0
Intercompany notes receivable	126,159		153,078
Property and equipment, at cost	156,973		142,527
Less - Accumulated depreciation and amortization	(29,157)		(23,556)
Property, plant and equipment, net	127,816		118,971
Goodwill	0		0
Other assets	38,973		48,190
Total assets	3,393,802		3,336,685
Current liabilities:
Accounts payable	365,253		208,230
Accrued liabilities	13,978		26,886
Current deferred taxes	(1,332)		88
Short-term borrowings and current maturities of long-term debt	230,353		25,678
Contingent consideration	0		0
Total current liabilities	608,252		260,882
Long-term debt, less current maturities	868,180		1,047,150
Intercompany notes payable	0		0
Accrued pension liabilities	0		0
Other liabilities and deferred credits	10,092		12,278
Deferred taxes	132,721		147,631
Redeemable noncontrolling interest	0		0
Common stock	378		377
Additional paid-in-capital	807,046		801,173
Retained earnings	1,072,411		1,172,273
Accumulated other comprehensive income (loss)	78,306		78,306
Treasury shares	(184,796)		(184,796)
Total Bristow Group stockholders' investment	1,773,345		1,867,333
Noncontrolling interests	1,212		1,411
Total stockholders' investment	1,774,557		1,868,744
Total liabilities, redeemable noncontrolling interests and stockholders' investment	3,393,802		3,336,685
Parent Company | Land and Building
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	4,842		4,776
Parent Company | Aircraft And Equipment
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	152,131		137,751
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0		3,393	828	884
Accounts receivable	642,332		353,729
Inventories	35,261		37,185
Assets held for sale	33,780		38,771
Prepaid expenses and other current assets	(1,852)		(1,843)
Total current assets	709,521		431,235
Intercompany investment	104,435		104,435
Investment in unconsolidated affiliates	0		0
Intercompany notes receivable	13,786		13,787
Property and equipment, at cost	1,157,585		1,206,805
Less - Accumulated depreciation and amortization	(256,037)		(238,644)
Property, plant and equipment, net	901,548		968,161
Goodwill	0		0
Other assets	2,306		743
Total assets	1,731,596		1,518,361
Current liabilities:
Accounts payable	619,569		475,118
Accrued liabilities	38,677		31,371
Current deferred taxes	(4,403)		1,914
Short-term borrowings and current maturities of long-term debt	1,926		0
Contingent consideration	0		0
Total current liabilities	655,769		508,403
Long-term debt, less current maturities	102,656		0
Intercompany notes payable	89,038		108,952
Accrued pension liabilities	0		0
Other liabilities and deferred credits	6,325		6,935
Deferred taxes	5,380		3,670
Redeemable noncontrolling interest	0		0
Common stock	20,028		4,996
Additional paid-in-capital	29,387		9,291
Retained earnings	823,013		876,114
Accumulated other comprehensive income (loss)	0		0
Treasury shares	0		0
Total Bristow Group stockholders' investment	872,428		890,401
Noncontrolling interests	0		0
Total stockholders' investment	872,428		890,401
Total liabilities, redeemable noncontrolling interests and stockholders' investment	1,731,596		1,518,361
Guarantor Subsidiaries | Land and Building
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	63,932		63,976
Guarantor Subsidiaries | Aircraft And Equipment
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	1,093,653		1,142,829
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	71,709		65,676	$ 130,359	$ 103,136
Accounts receivable	420,565		373,963
Inventories	89,097		105,318
Assets held for sale	3,855		5,012
Prepaid expenses and other current assets	51,435		49,978
Total current assets	636,661		599,947
Intercompany investment	124,801		145,168
Investment in unconsolidated affiliates	206,797		194,952
Intercompany notes receivable	3,600		3,600
Property and equipment, at cost	1,533,930		1,474,343
Less - Accumulated depreciation and amortization	(300,627)		(278,223)
Property, plant and equipment, net	1,233,303		1,196,120
Goodwill	18,793		29,990
Other assets	99,867		112,722
Total assets	2,323,822		2,282,499
Current liabilities:
Accounts payable	417,657		296,860
Accrued liabilities	139,392		401,031
Current deferred taxes	5,735		(121)
Short-term borrowings and current maturities of long-term debt	39,182		34,716
Contingent consideration	7,137		29,522
Total current liabilities	609,103		762,008
Long-term debt, less current maturities	19,371		24,428
Intercompany notes payable	136,826		81,422
Accrued pension liabilities	49,291		70,107
Other liabilities and deferred credits	10,039		14,060
Deferred taxes	11,860		20,953
Redeemable noncontrolling interest	8,267		15,473
Common stock	115,317		130,348
Additional paid-in-capital	284,048		284,048
Retained earnings	821,938		807,131
Accumulated other comprehensive income (loss)	254,038		63,248
Treasury shares	0		0
Total Bristow Group stockholders' investment	1,475,341		1,284,775
Noncontrolling interests	3,724		9,273
Total stockholders' investment	1,479,065		1,294,048
Total liabilities, redeemable noncontrolling interests and stockholders' investment	2,323,822		2,282,499
Non-Guarantor Subsidiaries | Land and Building
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	162,247		184,346
Non-Guarantor Subsidiaries | Aircraft And Equipment
Condensed Financial Statements, Captions [Line Items]
Property and equipment, at cost	$ 1,371,683		$ 1,289,997