Variable Interest Entities - Additional Information (Detail)				9 Months Ended						9 Months Ended			3 Months Ended		9 Months Ended						9 Months Ended				9 Months Ended
	Jan. 31, 2014 USD ($)	Apr. 30, 2013 USD ($)	Jan. 31, 2014 Atlantic USD ($)	Jan. 31, 2014 BHH - Brazilian Helicopter Holdings S.A. (BHH)	Jan. 31, 2014 Brazilian Investor	Jan. 31, 2014 EEA Helicopters Operations B.V. USD ($)	Jan. 31, 2014 EEA Helicopters Operations B.V. EUR (€)	Apr. 30, 2013 EEA Helicopters Operations B.V. USD ($)	Jan. 31, 2014 CHC Helicopters Canada Inc (CHC Canada)	Jan. 31, 2014 Nigerian Company Atlantic	Jan. 31, 2014 Thai Aviation Services	Jan. 31, 2014 Thai Investors	Jan. 31, 2014 Related Party Lessors USD ($)	Jan. 31, 2013 Related Party Lessors USD ($)	Jan. 31, 2014 Related Party Lessors USD ($)	Jan. 31, 2013 Related Party Lessors USD ($)	Apr. 30, 2013 Related Party Lessors USD ($)	Jan. 31, 2014 Other VIE lessors Lessor	Jan. 31, 2013 Other VIE lessors Lessor	Jan. 31, 2014 Atlantic USD ($)	Jan. 31, 2014 Common Class B EEA Helicopters Operations B.V.	Jan. 31, 2014 Common Class A European Investor	Jan. 31, 2014 Common Class A CHC Helicopters Canada Inc (CHC Canada)	Jan. 31, 2014 Common Class A Canadian Investor	Jan. 31, 2014 Class B Non-voting Preferred Shares CHC Helicopters Canada Inc (CHC Canada)	Jan. 31, 2014 Director CHC Helicopters Canada Inc (CHC Canada)	Jan. 31, 2014 Director Canadian Investor CHC Helicopters Canada Inc (CHC Canada)	Jan. 31, 2014 Director Common Class B EEA Helicopters Operations B.V.	Jan. 31, 2014 Director Common Class A EEA Helicopters Operations B.V.	Jan. 31, 2014 Aircraft Property Subject to Operating Lease Trinity Helicopters Limited	Jan. 31, 2014 Aircraft Property Subject to Operating Lease Related Party Lessors	Jan. 31, 2013 Aircraft Property Subject to Operating Lease Related Party Lessors	Jan. 31, 2014 Aircraft Property Subject to Operating Lease Other VIE lessors	Jan. 31, 2013 Aircraft Property Subject to Operating Lease Other VIE lessors
Variable Interest Entity [Line Items]
Percentage of ownership of common shares										100.00%	29.90%	70.10%									49.90%	50.10%	25.00%		100.00%
Number of common shares owned																					9,896,085		200,000		200,000
Number Of Common Shares Owned by European Investor																						9,935,750
Management Board Composition, by Nomination																										1	2	1	3
Ownership of shares in profit certificates						7,000,000	7,000,000
Par value of shares in profit certificates							€ 1
Percentage of cumulative annual dividend of issue price of each Profit Certificate						30.00%	30.00%
Cumulative annual dividend							€ 2,100,000
Initial period to receive specific percentage of dividend on Profit Certificates						7 years	7 years
Percentage of cumulative annual dividend of issue price of each Profit Certificate after specific number of years						5.00%	5.00%
Cumulative annual dividend after 7 years of issuance							350,000
Redeemable non-controlling interests	(5,612,000)	(8,262,000)				(6,600,000)		(8,300,000)												1,000,000
Percentage of interest				60.00%
Percentage of Non-voting preferred shares owned				100.00%
Percentage of ordinary voting shares				20.00%	80.00%
Margin percentage on original capital contribution to calculate Put or Call Price				2.00%					6.00%
Remaining number of common shares owned																								600,000
Remaining percentage of common shares owned																						50.10%		75.00%
VIE Agreement Terms										The Nigerian Company’s risks and rewards are not representative of its equity interest as it is only entitled to management fees for the first four years of the agreement. In the fifth year the Nigerian Company can opt to receive 40% of the profits or losses or continue with the existing arrangement. We will bear the risk for substantially all of the losses for the first four years of the arrangement.
Contingent credit available			10,000,000
Operating lease expense													12,600,000	12,500,000	37,800,000	35,300,000
Operating lease expense outstanding in payables and accruals	270,004,000												4,000,000		4,000,000		4,500,000
Receivables, due		$ 100,000											$ 8,100,000		$ 8,100,000		$ 5,100,000
Number of aircraft under operating lease agreements																														2	31	31	47	17
Number of lessor																		4	2
Option available on the fifth year for variable interest entity ownership percentage to receive profit or losses										40.00%