Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2013 Case	Mar. 31, 2013 2013 [Member]	Mar. 31, 2013 2014 [Member]	Mar. 31, 2013 2016 [Member]	Mar. 31, 2013 2017 [Member]	Mar. 31, 2013 2019 [Member]	Mar. 31, 2013 Light Helicopters [Member] Aircraft	Mar. 31, 2013 Light Helicopters [Member] 2013 [Member] Aircraft	Dec. 31, 2012 Heavy Transport Aircraft [Member] Aircraft
Commitments and Contingencies (Textual) [Abstract]
Number of aircrafts acquire under contract									6
Aggregate acquisition cost related to aircraft	$ 160.3							$ 5.1
Number of helicopters scheduled to be acquired								2
Number of light helicopters acquired							10
Aggregate purchase price for aircraft		38.8	114.4	33.5	89.8	19.5
Commitments and Contingencies (Additional Textual) [Abstract]
Total aircraft deposits	12.4
Aggregate estimated probable liability environmental matters	0.2
Period of initial work	21 days
Number of other suits between the parties involved for pending case	2
Aggregate commitments under operating leases	201.3
Operational lease payable at Dec 31,2013	31.7
Lease commitment for aircraft	181.2
Facility lease commitments	$ 20.1