v3.7.0.1
Condensed Consolidating Financial Information - Guarantor Subsidiaries - Condensed Consolidating Statements of Cash Flows (Detail) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]    
Net cash (used in) provided by operating activities $ (8,253) $ (16,343)
Investing activities:    
Purchase of property and equipment (4,789) (8,519)
Proceeds from asset dispositions   850
Purchase of short-term investments (54,867) (77,677)
Proceeds from sale of short-term investments 67,659 76,184
Payments of deposits on aircraft (66) (66)
Net cash provided by (used in) investing activities 7,937 (9,228)
Financing activities:    
Proceeds from line of credit 37,300 83,500
Payments on line of credit (35,800) (53,300)
Repurchase of common stock (100) (500)
Net cash provided by (used in) financing activities 1,400 29,700
Increase in cash 1,084 4,129
Cash, beginning of period 2,596 2,407
Cash, end of period 3,680 6,536
Parent Company Only (issuer) [Member]    
Condensed Cash Flow Statements, Captions [Line Items]    
Net cash (used in) provided by operating activities (19,332) (13,795)
Investing activities:    
Purchase of property and equipment (4,738) (8,519)
Proceeds from asset dispositions   850
Purchase of short-term investments (54,867) (77,677)
Proceeds from sale of short-term investments 67,659 76,184
Payments of deposits on aircraft (66) (66)
Net cash provided by (used in) investing activities 7,988 (9,228)
Financing activities:    
Proceeds from line of credit 37,300 83,500
Payments on line of credit (35,800) (53,300)
Repurchase of common stock (100) (500)
Due to/from affiliate, net 9,959 (6,600)
Net cash provided by (used in) financing activities 11,359 23,100
Increase in cash 15 77
Cash, beginning of period 36 46
Cash, end of period 51 123
Guarantor Subsidiaries [Member]    
Condensed Cash Flow Statements, Captions [Line Items]    
Net cash (used in) provided by operating activities [1] 11,079 (2,548)
Investing activities:    
Purchase of property and equipment [1] (51)  
Net cash provided by (used in) investing activities [1] (51)  
Financing activities:    
Due to/from affiliate, net [1] (9,959) 6,600
Net cash provided by (used in) financing activities [1] (9,959) 6,600
Increase in cash [1] 1,069 4,052
Cash, beginning of period [1] 2,560 2,361
Cash, end of period [1] $ 3,629 $ 6,413
[1] Foreign subsidiaries represent minor subsidiaries and are included in the guarantor subsidiaries' amounts.