Commitments and Contingencies - Additional Information (Detail) $ in Millions		3 Months Ended	9 Months Ended	12 Months Ended
	Oct. 01, 2016 USD ($) Aircraft	Sep. 30, 2016 USD ($) Aircraft	Sep. 30, 2016 USD ($) Land_Parcel	Dec. 31, 2015 Aircraft	Dec. 31, 2014 Aircraft
Long-term Purchase Commitment [Line Items]
Number of aircrafts delivered | Aircraft				1
Total aircraft deposits		$ 2.8	$ 2.8
Aggregate estimated probable liability environmental matters		0.2	$ 0.2
Number of parcels of land exists | Land_Parcel			2
Aggregate commitments under operating leases		239.0	$ 239.0
Operational lease payable		12.0	12.0
Lease commitment for aircraft		226.2	226.2
Facility lease commitments		12.8	12.8
2016 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft			50.3
2017 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft			55.7
2018 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft			127.0
2019 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft			150.4
2020 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft			$ 22.7
Heavy Aircraft [Member]
Long-term Purchase Commitment [Line Items]
Option to purchase additional number of aircrafts | Aircraft					6
Number of aircraft orders cancelled previously scheduled for delivery | Aircraft				4
Aggregate purchase price for aircraft		$ 26.7
Number of aircraft purchased | Aircraft		1
Medium Aircraft [Member] | Subsequent Event [Member] | Oil and Gas [Member]
Long-term Purchase Commitment [Line Items]
Number of aircrafts acquired under contract | Aircraft	2
Purchase commitment for aircraft	$ 19.9