QUARTERLY FINANCIAL INFORMATION (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Unusual or Infrequent Item [Line Items]
Gross revenue	$ 381,719	$ 419,887	$ 446,911	$ 466,996	$ 450,355	$ 460,140	$ 475,636	$ 472,538	$ 1,715,513	$ 1,858,669	$ 1,669,582
Operating income (loss)	(37,923)	22,077	(29,833)	4,834	27,702	8,916	44,064	65,192	(40,845)	145,874	186,977
Net income (loss) attributable to Bristow Group	$ (25,255)	$ 3,202	$ (47,132)	$ (3,257)	$ 15,077	$ (968)	$ 26,082	$ 44,109	$ (72,442)	$ 84,300	$ 186,737
Basic earnings (loss) per share	$ (0.72)	$ 0.09	$ (1.21)	$ (0.27)	$ 0.43	$ (0.03)	$ 0.74	$ 1.24	$ (2.12)	$ 2.40	$ 5.15
Diluted earnings (loss) per share	$ (0.72)	$ 0.09	$ (1.21)	$ (0.27)	$ 0.43	$ (0.03)	$ 0.73	$ 1.23	$ (2.12)	$ 2.37	$ 5.09
Gain (loss) on disposal of assets	$ (6,800)	$ (2,200)	$ (14,000)	$ (7,700)	$ (10,300)	$ (26,300)	$ 100	$ 600	$ (30,693)	$ (35,849)	$ (722)
Organizational restructuring
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net	(5,900)
Unusual or infrequent item, net income impact, net	$ (2,300)
Unusual or infrequent item, earnings per share impact, net	$ (0.07)
Employee severance
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net		(7,300)	(5,700)	(8,000)	(900)		(1,800)	(3,700)
Unusual or infrequent item, net income impact, net		$ (5,400)	$ (4,200)	$ (5,600)	$ (600)		$ (1,200)	$ (2,400)
Unusual or infrequent item, earnings per share impact, net		$ (0.15)	$ (0.12)	$ (0.16)	$ (0.02)		$ (0.03)	$ (0.07)
Accelerated depreciation
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net	$ (3,600)	$ (5,000)	$ (10,500)	$ (10,500)
Unusual or infrequent item, net income impact, net	$ (3,200)	$ (3,800)	$ (7,900)	$ (7,900)
Unusual or infrequent item, earnings per share impact, net	$ (0.09)	$ (0.11)	$ (0.22)	$ (0.23)
Inventory valuation
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net				$ (5,400)		(3,800)	$ (3,400)
Unusual or infrequent item, net income impact, net				$ (3,500)		$ (3,000)	$ (2,700)
Unusual or infrequent item, earnings per share impact, net				$ (0.10)		$ (0.09)	$ (0.08)
Accretion of noncontrolling interest
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, earnings per share impact, net			$ 0.14	$ (0.18)
North America restructuring
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net							$ (600)	$ (1,000)
Unusual or infrequent item, net income impact, net							$ (400)	$ (700)
Unusual or infrequent item, earnings per share impact, net							$ (0.01)	$ (0.02)
Repurchase of debt
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net						$ (600)	$ (800)	$ (700)
Unusual or infrequent item, earnings per share impact, net						$ (0.02)	$ (0.02)	$ (0.02)
Impairment of goodwill
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net	$ (27,400)		$ (22,300)
Unusual or infrequent item, net income impact, net	$ (15,700)		$ (25,600)
Unusual or infrequent item, earnings per share impact, net	$ (0.44)		$ (0.73)
Tax valuation allowance
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net	$ (5,100)	$ (9,500)
Unusual or infrequent item, earnings per share impact, net	$ (0.14)	$ (0.27)
Adjustments for error correction
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net						$ (5,300)
Unusual or infrequent item, net income impact, net						$ (4,200)
Unusual or infrequent item, earnings per share impact, net						$ (0.12)
Cost reversal
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net						$ 800
Unusual or infrequent item, net income impact, net						$ 600
Unusual or infrequent item, earnings per share impact, net						$ 0.02
Sale of affiliate
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net						$ 2,500
Unusual or infrequent item, earnings per share impact, net						$ 0.07
Fleet change
Unusual or Infrequent Item [Line Items]
Unusual or Infrequent item, operating income impact, net					$ (10,400)
Unusual or infrequent item, net income impact, net					$ (8,000)
Unusual or infrequent item, earnings per share impact, net					$ (0.23)
Disposal of assets
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net	$ (3,700)	$ (1,700)	$ (10,800)	$ (5,900)	$ (8,100)	$ (21,000)	$ 100	$ 500
Unusual or infrequent item, earnings per share impact, net	$ (0.10)	$ (0.05)	$ (0.31)	$ (0.17)	$ (0.23)	$ (0.60)	$ 0.00	$ 0.01