Segment Information - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			3 Months Ended
	Mar. 31, 2014 Contract Entity	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2014 Hospitals Contracts [Member]	Mar. 31, 2013 Hospitals Contracts [Member]	Mar. 31, 2014 Oil And Gas [Member] Aircraft	Mar. 31, 2013 Oil And Gas [Member]	Mar. 31, 2014 Oil And Gas [Member] Minimum [Member] Major Customer [Member]	Mar. 31, 2014 Oil And Gas [Member] Minimum [Member] ENI Petroleum [Member]	Mar. 31, 2014 Air Medical [Member] Aircraft Location States	Mar. 31, 2013 Air Medical [Member]	Mar. 31, 2014 Air Medical [Member] Middle East [Member] Location Aircraft	Mar. 31, 2014 Technical Services [Member]	Mar. 31, 2013 Technical Services [Member]
Segment Reporting Information [Line Items]
Working period with major customers								30 years	15 years
Number of Aircraft Operated						168				92		9
Segment revenue				42.00%	39.00%	64.00%	63.00%			34.00%	35.00%		2.00%	2.00%
Number of Aircraft Assigned										101
Number of states in which company operates aircrafts										18
Locations in which company operates Aircrafts										72		6
Number of Contracts	0
Fixed Revenue Streams	0
Allowance for contractual discounts	$ 76.0	$ 74.7	$ 57.5
Allowance for uncompensated care	$ 43.9	$ 46.4	$ 49.3