QUARTERLY FINANCIAL INFORMATION (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Unusual or Infrequent Item [Line Items]
Revenues	$ 450,355,000	$ 460,140,000	$ 475,636,000	$ 472,538,000	$ 440,925,000	$ 412,335,000	$ 417,328,000	$ 398,994,000	$ 1,858,669,000	$ 1,669,582,000	$ 1,508,473,000
Operating income	27,702,000	8,916,000	44,064,000	65,192,000	47,421,000	29,502,000	53,935,000	56,119,000	145,874,000	186,977,000	224,144,000
Net income attributable to Bristow Group	15,077,000	(968,000)	26,082,000	44,109,000	30,318,000	18,927,000	110,606,000	26,886,000	84,300,000	186,737,000	130,102,000
Basic earnings per share	$ 0.43	$ (0.03)	$ 0.74	$ 1.24	$ 0.84	$ 0.52	$ 3.04	$ 0.74	$ 2.40	$ 5.15	$ 3.61
Diluted earnings per share	$ 0.43	$ (0.03)	$ 0.73	$ 1.23	$ 0.83	$ 0.51	$ 3.01	$ 0.74	$ 2.37	$ 5.09	$ 3.57
Extinguishment of debt									(2,591,000)	0	(14,932,000)
Gain (loss) on disposal of assets	(10,300,000)	(26,300,000)	100,000	600,000	100,000	4,000,000	(3,100,000)	(1,700,000)	(35,849,000)	(722,000)	8,068,000
North America restructuring [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net			(600,000)	(1,000,000)	(800,000)	(2,100,000)	(500,000)
Unusual Or Infrequent Item Net Income Impact Net			(400,000)	(700,000)	(500,000)	(1,400,000)	(400,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net			$ (0.01)	$ (0.02)	$ (0.01)	$ (0.04)	$ (0.01)
Employee severance [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net	(900,000)		(1,800,000)	(3,700,000)	(4,800,000)
Unusual Or Infrequent Item Net Income Impact Net	(600,000)		(1,200,000)	(2,400,000)	(3,100,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net	$ (0.02)		$ (0.03)	$ (0.07)	$ (0.09)
Repurchase of debt [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Net Income Impact Net		(600,000)	(800,000)	(700,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net		$ (0.02)	$ (0.02)	$ (0.02)
Inventory valuation reserve [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net		(3,800,000)	(3,400,000)		(10,500,000)		(1,500,000)	(800,000)
Unusual Or Infrequent Item Net Income Impact Net		(3,000,000)	(2,700,000)		(8,400,000)		(1,000,000)	(500,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net		$ (0.09)	$ (0.08)		$ (0.23)		$ (0.03)	$ (0.01)
Adjustments for error correction [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net		(5,300,000)
Unusual Or Infrequent Item Net Income Impact Net		(4,200,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net		$ (0.12)
Cost reversal [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net		800,000
Unusual Or Infrequent Item Net Income Impact Net		600,000
Unusual or Infrequent Item, Earnings Per Share Impact, Net		$ 0.02
Sale of affiliate [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Net Income Impact Net		2,500,000					67,900,000
Unusual or Infrequent Item, Earnings Per Share Impact, Net		$ 0.07					$ 1.85
Damage from fire, explosion or other hazard [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net					(8,600,000)
Unusual Or Infrequent Item Net Income Impact Net					(6,600,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net					$ (0.18)
Goodwill [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net					(600,000)
Unusual Or Infrequent Item Net Income Impact Net					(400,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net					$ (0.01)
Cancellation of potential financing [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Net Income Impact Net								(8,300,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net								$ (0.23)
Contract termination [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net						(2,100,000)
Unusual Or Infrequent Item Net Income Impact Net						(1,600,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net						$ (0.04)
Tax amnesty [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net					4,200,000	(19,300,000)
Unusual Or Infrequent Item Net Income Impact Net					2,800,000	(12,600,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net					$ 0.08	$ (0.34)
Fleet change [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Operating Income Impact Net	(10,400,000)
Unusual Or Infrequent Item Net Income Impact Net	(8,000,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net	$ (0.23)
Disposal of assets [Member]
Unusual or Infrequent Item [Line Items]
Unusual Or Infrequent Item Net Income Impact Net	$ (8,100,000)	$ (21,000,000)	$ 100,000	$ 500,000	$ 100,000	$ 3,100,000	$ (2,400,000)	$ (1,300,000)
Unusual or Infrequent Item, Earnings Per Share Impact, Net	$ (0.23)	$ (0.60)	$ 0.00	$ 0.01	$ 0.00	$ 0.09	$ (0.07)	$ (0.04)