Summary of Significant Accounting Policies - Schedule of Net Revenue Attributable to Medicaid, Medicare Insurance and Self Pay as Percentage of Net Air Medical Revenues (Detail) (Air Medical [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Insurance [Member]
Segment Reporting Information [Line Items]
Percentage of net Air Medical revenues	74.00%	73.00%	69.00%
Medicare [Member]
Segment Reporting Information [Line Items]
Percentage of net Air Medical revenues	18.00%	19.00%	21.00%
Medicaid [Member]
Segment Reporting Information [Line Items]
Percentage of net Air Medical revenues	8.00%	7.00%	9.00%
Self Pay [Member]
Segment Reporting Information [Line Items]
Percentage of net Air Medical revenues	0.00%	1.00%	1.00%