v3.5.0.2
Segment Information - Schedule of Financial Information Concerning Reportable Operating Segments (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Segment Reporting Information [Line Items]        
Total operating revenues, net $ 167,136 $ 198,547 $ 331,152 $ 402,744
Total direct expenses 152,417 168,828 304,971 338,035
Total segment selling, general and administrative expenses 11,778 12,047 23,451 23,284
Total 7,163 17,632 6,593 41,324
Interest expense (7,540) (7,155) (15,073) (14,325)
Earnings (loss) before income taxes 117 11,044 (7,371) 28,028
Reportable Operating Segments [Member]        
Segment Reporting Information [Line Items]        
Total operating revenues, net 167,136 198,547 331,152 402,744
Total direct expenses [1] 152,493 168,934 305,047 338,209
Total segment selling, general and administrative expenses 4,520 4,010 8,866 7,912
Total segment expenses 157,013 172,944 313,913 346,121
Total 10,123 25,603 17,239 56,623
Reportable Operating Segments [Member] | Air Medical [Member]        
Segment Reporting Information [Line Items]        
Total operating revenues, net 75,547 81,642 145,607 154,027
Total direct expenses [1] 58,997 63,576 116,041 123,615
Total segment selling, general and administrative expenses 2,642 2,527 5,237 5,156
Total 13,908 15,539 24,329 25,256
Reportable Operating Segments [Member] | Oil and Gas [Member]        
Segment Reporting Information [Line Items]        
Total operating revenues, net 83,185 112,839 171,622 233,235
Total direct expenses [1],[2] 87,400 100,262 179,316 200,593
Total segment selling, general and administrative expenses 1,605 1,275 3,132 2,434
Total (5,820) 11,302 (10,826) 30,208
Reportable Operating Segments [Member] | Technical Services [Member]        
Segment Reporting Information [Line Items]        
Total operating revenues, net 8,404 4,066 13,923 15,482
Total direct expenses [1] 6,096 5,096 9,690 14,001
Total segment selling, general and administrative expenses 273 208 497 322
Total 2,035 (1,238) 3,736 1,159
Segment Reconciling Items [Member]        
Segment Reporting Information [Line Items]        
Other, net [3] 4,792 633 5,048 1,102
Interest expense (7,540) (7,155) (15,073) (14,325)
Unallocated Selling, General and Administrative Expenses [Member]        
Segment Reporting Information [Line Items]        
Unallocated selling, general and administrative costs [1] $ (7,258) $ (8,037) $ (14,585) $ (15,372)
[1] Included in direct expenses and unallocated selling, general and administrative costs are the depreciation and amortization expense amounts below: Depreciation and Amortization Expense Quarter Ended June 30, Six Months Ended June 30, Segment Direct Expense: 2016 2015 2016 2015 Oil and Gas $ 10,024 $ 10,323 $ 19,942 $ 21,603 Air Medical 5,132 4,750 9,387 8,848 Technical Services 157 132 285 260 Total $ 15,313 $ 15,205 $ 29,614 $ 30,711 Unallocated SG&A $ 2,476 $ 3,155 $ 5,147 $ 5,801
[2] Includes Equity in loss of unconsolidated affiliate.
[3] Consists of gains on disposition of property and equipment, and other income.