Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014 Aircraft	Dec. 31, 2013 Aircraft
Long-term Purchase Commitment [Line Items]
Total aircraft deposits	$ 15.9
Aggregate estimated probable liability environmental matters	0.2
Aggregate commitments under operating leases	251.5
Operational lease payable	36.2
Lease commitment for aircraft	234.1
Facility lease commitments	17.4
Heavy Helicopters [Member]
Long-term Purchase Commitment [Line Items]
Number of aircrafts acquire under contract		6
Number of aircrafts delivered under contract	1
Option to purchase additional number of aircraft	6
Aircraft purchased	6
2014 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft	88.9
2016 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft	33.5
2017 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft	89.8
2019 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft	$ 19.5