SEGMENT INFORMATION - Schedule of Profit or Loss and Assets of Each of the Company's Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Total operating revenues, net	$ 195,543	$ 160,554	$ 374,511	$ 298,605
Total direct expenses	159,494	134,088	307,697	252,790
Total selling, general and administrative expenses	10,024	9,672	18,290	18,508
Total direct and selling, general and administrative expenses	163,026	136,719	314,469	257,974
Total net segment profit (loss)	39,709	17,473	61,696	27,997
Interest expense	(7,257)	(7,440)	(14,666)	(14,640)
Earnings before income taxes	32,525	10,090	47,255	13,720
Reportable operating segments [Member] | Oil and Gas Properties [Member]
Segment Reporting Information [Line Items]
Total operating revenues, net	120,970	104,421	233,801	197,373
Total direct expenses	97,824	89,252	190,697	169,266
Total selling, general and administrative expenses	1,027	911	1,940	1,808
Total net segment profit (loss)	22,119	14,258	41,164	26,299
Reportable operating segments [Member] | Air Medical [Member]
Segment Reporting Information [Line Items]
Total operating revenues, net	72,859	54,399	136,246	96,553
Total direct expenses	60,376	42,847	114,372	80,003
Total selling, general and administrative expenses	1,909	1,720	3,749	3,375
Total net segment profit (loss)	10,574	9,832	18,125	13,175
Reportable operating segments [Member] | Technical Services [Member]
Segment Reporting Information [Line Items]
Total operating revenues, net	1,714	1,734	4,464	4,679
Total direct expenses	1,890	1,989	3,711	3,521
Total selling, general and administrative expenses				1
Total net segment profit (loss)	(176)	(255)	753	1,157
Other, Net [Member]
Segment Reporting Information [Line Items]
Total net segment profit (loss)	14,353	736	14,480	1,053
Unallocated S,G & A [Member]
Segment Reporting Information [Line Items]
Total net segment profit (loss)	$ (7,088)	$ (7,041)	$ (12,601)	$ (13,324)