QUARTERLY FINANCIAL INFORMATION (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Total consolidated gross revenue	$ 391,642,000	$ 388,469,000	$ 365,754,000	$ 362,608,000	$ 358,371,000	$ 331,335,000	$ 330,992,000	$ 321,105,000	$ 1,508,473,000	$ 1,341,803,000	$ 1,232,808,000
Operating income	62,703,000	74,120,000	47,328,000	39,993,000	26,213,000	43,553,000	9,595,000	36,405,000	224,144,000	115,766,000	189,724,000
Net income attributable to Bristow	40,380,000	36,392,000	29,668,000	23,662,000	14,242,000	25,532,000	2,711,000	21,045,000	130,102,000	63,530,000	132,315,000
Basic earnings per share	$ 1.12	$ 1.01	$ 0.83	$ 0.66	$ 0.40	$ 0.71	$ 0.07	$ 0.58	$ 3.61	$ 1.76	$ 3.67
Diluted earnings per share	$ 1.11	$ 1.00	$ 0.82	$ 0.65	$ 0.39	$ 0.70	$ 0.07	$ 0.57	$ 3.57	$ 1.73	$ 3.60
Work force reductions costs									2,200,000
Impairment of inventories									0	25,919,000	0
Extinguishment of debt									(14,932,000)	0	(2,300,000)
Write off of deferred debt issuance cost									4,642,000	0	0
Cost Method Investment Dividends Or Distributions									28,000	2,397,000	2,649,000
Gain (loss) on disposal of assets									8,068,000	(31,670,000)	8,678,000
AS332L Aircraft [Member]
Quarterly Financial Information Disclosure [Abstract]
Impairment Number Title Transfer After					2
Medium Aircraft [Member]
Quarterly Financial Information Disclosure [Abstract]
Impairment of Long-Lived Assets										(2,690,000)
Senior Notes Due 2017 [Member]
Quarterly Financial Information Disclosure [Abstract]
Extinguishment of debt		(14,932,000)
Write off of deferred debt issuance cost		(2,600,000)
Three Hundred Sixty Four Day Term Loan And Credit Facility [Member]
Quarterly Financial Information Disclosure [Abstract]
Write off of deferred debt issuance cost									2,100,000
Creole, Louisiana [Member]
Quarterly Financial Information Disclosure [Abstract]
Impairment from abandonment of certain assets										2,700,000
Operating Income [Member]
Quarterly Financial Information Disclosure [Abstract]
Calculation errors costs			2,800,000
Impairment of inventories	(2,800,000)				(1,300,000)		(24,600,000)
Cost Method Investment Dividends Or Distributions					2,000,000
Gain (loss) on disposal of assets	7,200,000	7,400,000	(1,300,000)	(5,300,000)	(28,600,000)	(2,900,000)	(1,600,000)	1,400,000
Operating Income [Member] | AS332L Aircraft [Member]
Quarterly Financial Information Disclosure [Abstract]
Direct cost aircraft sale					(2,100,000)					(2,100,000)
Operating Income [Member] | Medium Aircraft [Member]
Quarterly Financial Information Disclosure [Abstract]
Direct cost aircraft sale	900,000								900,000
Impairment of Long-Lived Assets					(2,700,000)
Operating Income [Member] | Southern North Sea [Member]
Quarterly Financial Information Disclosure [Abstract]
Work force reductions costs				(2,200,000)
Operating Income [Member] | Creole, Louisiana [Member]
Quarterly Financial Information Disclosure [Abstract]
Impairment from abandonment of certain assets							(2,700,000)
Net Income Member
Quarterly Financial Information Disclosure [Abstract]
Calculation errors costs			1,800,000
Impairment of inventories	(2,200,000)				(900,000)		(17,600,000)
Cost Method Investment Dividends Or Distributions					1,300,000
Increase in tax expense for certain items					(800,000)
Gain (loss) on disposal of assets	5,500,000	6,100,000	(1,000,000)	(4,200,000)	(24,500,000)	(2,300,000)	(1,300,000)	1,100,000
Net Income Member | AS332L Aircraft [Member]
Quarterly Financial Information Disclosure [Abstract]
Direct cost aircraft sale	700,000				(1,400,000)				700,000	(1,400,000)
Net Income Member | Medium Aircraft [Member]
Quarterly Financial Information Disclosure [Abstract]
Impairment of Long-Lived Assets					(2,700,000)
Net Income Member | Senior Notes Due 2017 [Member]
Quarterly Financial Information Disclosure [Abstract]
Debt Extinguishment And Write off of deferred debt issuance cost		(11,400,000)
Net Income Member | Three Hundred Sixty Four Day Term Loan And Credit Facility [Member]
Quarterly Financial Information Disclosure [Abstract]
Write off of deferred debt issuance cost	(600,000)	(1,000,000)
Net Income Member | Southern North Sea [Member]
Quarterly Financial Information Disclosure [Abstract]
Work force reductions costs				(1,700,000)
Net Income Member | Creole, Louisiana [Member]
Quarterly Financial Information Disclosure [Abstract]
Impairment from abandonment of certain assets							(1,700,000)
Earnings Per Share Diluted [Member]
Quarterly Financial Information Disclosure [Abstract]
Calculation errors costs			0.05
Impairment of inventories	(0.06)				(0.03)		(0.48)
Cost Method Investment Dividends Or Distributions					0.04
Increase in tax expense for certain items					(0.02)
Gain (loss) on disposal of assets	0.15	0.17	(0.03)	(0.12)	(0.67)	(0.06)	(0.03)	0.03
Earnings Per Share Diluted [Member] | AS332L Aircraft [Member]
Quarterly Financial Information Disclosure [Abstract]
Direct cost aircraft sale	0.02				(0.04)				0.02	(0.04)
Earnings Per Share Diluted [Member] | Medium Aircraft [Member]
Quarterly Financial Information Disclosure [Abstract]
Impairment of Long-Lived Assets					(0.07)
Earnings Per Share Diluted [Member] | Senior Notes Due 2017 [Member]
Quarterly Financial Information Disclosure [Abstract]
Debt Extinguishment And Write off of deferred debt issuance cost		(0.31)
Earnings Per Share Diluted [Member] | Three Hundred Sixty Four Day Term Loan And Credit Facility [Member]
Quarterly Financial Information Disclosure [Abstract]
Write off of deferred debt issuance cost	(0.01)	(0.03)
Earnings Per Share Diluted [Member] | Southern North Sea [Member]
Quarterly Financial Information Disclosure [Abstract]
Work force reductions costs				(0.05)
Earnings Per Share Diluted [Member] | Creole, Louisiana [Member]
Quarterly Financial Information Disclosure [Abstract]
Impairment from abandonment of certain assets							$ (0.05)