QUARTERLY FINANCIAL INFORMATION (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Unusual or Infrequent Item [Line Items]
Gross revenue	$ 336,194	$ 337,443	$ 357,467	$ 369,398	$ 381,719	$ 419,887	$ 446,911	$ 466,996	$ 1,400,502	$ 1,715,513	$ 1,858,669
Operating income (loss)	(19,528)	(19,097)	(26,882)	(26,235)	(37,923)	22,077	(29,833)	4,834	(91,742)	(40,845)	145,874
Net income (loss) attributable to Bristow Group	$ (78,040)	$ (21,927)	$ (29,797)	$ (40,772)	$ (25,255)	$ 3,202	$ (47,132)	$ (3,257)	$ (170,536)	$ (72,442)	$ 84,300
Basic earnings (loss) per share	$ (2.22)	$ (0.62)	$ (0.85)	$ (1.17)	$ (0.72)	$ 0.09	$ (1.21)	$ (0.27)	$ (4.87)	$ (2.12)	$ 2.40
Diluted earnings (loss) per share	$ (2.22)	$ (0.62)	$ (0.85)	$ (1.17)	$ (0.72)	$ 0.09	$ (1.21)	$ (0.27)	$ (4.87)	$ (2.12)	$ 2.37
Gain (loss) on disposal of assets	$ (1,400)	$ (900)	$ (2,200)	$ (10,000)	$ (6,800)	$ (2,200)	$ (14,000)	$ (7,700)	$ (14,499)	$ (30,693)	$ (35,849)
Organizational restructuring
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net	$ (2,100)	$ (600)	$ (7,300)	$ (4,300)	$ (2,300)
Unusual or infrequent item, earnings per share impact, net	$ (0.06)	$ (0.02)	$ (0.21)	$ (0.12)	$ (0.07)
Unusual or Infrequent Item, or Both, Net (Gain) Loss	$ (2,800)	$ (800)	$ (10,700)	$ (6,600)	$ (5,900)
Employee severance
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net						$ (5,400)	$ (4,200)	$ (5,600)
Unusual or infrequent item, earnings per share impact, net						$ (0.15)	$ (0.12)	$ (0.16)
Unusual or Infrequent Item, or Both, Net (Gain) Loss						$ (7,300)	$ (5,700)	$ (8,000)
Accelerated depreciation
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net	$ (700)	$ (800)	$ (900)	$ (4,500)	$ (3,200)	$ (3,800)	$ (7,900)	$ (7,900)
Unusual or infrequent item, earnings per share impact, net	$ (0.02)	$ (0.02)	$ (0.02)	$ (0.13)	$ (0.09)	$ (0.11)	$ (0.22)	$ (0.23)
Unusual or Infrequent Item, or Both, Net (Gain) Loss	$ (1,100)	$ (1,100)	$ (1,300)	$ (6,900)	$ (3,600)	$ (5,000)	$ (10,500)	$ (10,500)
Inventory impairment
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net			$ (5,300)					$ (3,500)
Unusual or infrequent item, earnings per share impact, net			$ (0.15)					$ (0.10)
Unusual or Infrequent Item, or Both, Net (Gain) Loss			$ (7,600)					$ (5,400)
Accretion of noncontrolling interest
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, earnings per share impact, net							$ 0.14	$ (0.18)
Impairment of goodwill
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net		$ (7,900)			$ (15,700)		$ (25,600)
Unusual or infrequent item, earnings per share impact, net		$ (0.22)			$ (0.44)		$ (0.73)
Unusual or Infrequent Item, or Both, Net (Gain) Loss		$ (8,700)			$ (27,400)		$ (22,300)
Tax items
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net	$ (40,000)	$ (3,700)	$ (2,500)	$ (13,200)	$ (5,100)	$ (9,500)
Unusual or infrequent item, earnings per share impact, net	$ (1.14)	$ (0.10)	$ (0.07)	$ (0.38)	$ (0.14)	$ (0.27)
Disposal of assets
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net	$ (800)	$ 1,100	$ (1,500)	$ (6,800)	$ (3,700)	$ (1,700)	$ (10,800)	$ (5,900)
Unusual or infrequent item, earnings per share impact, net	$ (0.02)	$ 0.03	$ (0.04)	$ (0.19)	$ (0.10)	$ (0.05)	$ (0.31)	$ (0.17)
Reversal of contingent consideration
Unusual or Infrequent Item [Line Items]
Unusual or infrequent item, net income impact, net	$ 5,900
Unusual or infrequent item, earnings per share impact, net	$ 0.17
Unusual or Infrequent Item, or Both, Net (Gain) Loss	$ 5,900