Bristow Group Inc. Annual report pursuant to Section 13 and 15(d)

COMMON STOCK Narrative (Details) (USD $)	0 Months Ended
COMMON STOCK Narrative (Details) (USD $)	Jan. 31, 2013	Aug. 01, 2011 vote	Jul. 31, 2011
Class of Stock [Line Items]
Common stock, par value	$ 0.01
Common stock issued (in shares)	19,883,583
Common Class A [Member]
Class of Stock [Line Items]
Common stock, shares authorized			60,000,000
Common stock, par value			$ 0.01
Number of votes per share		1
Common Class B [Member]
Class of Stock [Line Items]
Common stock, shares authorized			60,000,000
Common stock, par value			$ 0.01
Common stock issued (in shares)		24,500
Number of votes per share		8
Shares owned by affiliates percent minimum for conversion		20.00%