v3.8.0.1

Condensed Consolidating Financial Information - Guarantor Subsidiaries - Condensed Consolidating Statements of Cash Flows (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ (1,868)	$ (7,148)
Investing activities:
Purchase of property and equipment	(49,227)	(74,950)
Proceeds from asset dispositions	21	13,233
Purchase of short-term investments	(268,525)	(263,204)
Proceeds from sale of short-term investments	354,250	259,322
Payments of deposits on aircraft	0	(197)
Loan to unconsolidated affiliate	0	(1,200)
Net cash provided by (used in) investing activities	36,519	(66,996)
Financing activities:
Proceeds from line of credit	99,150	213,900
Payments on line of credit	(133,150)	(139,000)
Repurchase of common stock	(256)	(524)
Net cash (used in) provided by financing activities	(34,256)	74,376
Increase (decrease) in cash	395	232
Cash, beginning of period	2,596	2,407
Cash, end of period	2,991	2,639
Parent Company Only (issuer) [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(43,328)	(32,467)
Investing activities:
Purchase of property and equipment	(49,227)	(74,647)
Proceeds from asset dispositions	21	13,233
Purchase of short-term investments	(268,525)	(263,204)
Proceeds from sale of short-term investments	354,250	259,322
Payments of deposits on aircraft		(197)
Loan to unconsolidated affiliate		(1,200)
Net cash provided by (used in) investing activities	36,519	(66,693)
Financing activities:
Proceeds from line of credit	99,150	213,900
Payments on line of credit	(133,150)	(139,000)
Repurchase of common stock	(256)	(524)
Due to/from affiliate, net	41,079	24,774
Net cash (used in) provided by financing activities	6,823	99,150
Increase (decrease) in cash	14	(10)
Cash, beginning of period	36	46
Cash, end of period	50	36
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	33,670	25,319
Investing activities:
Purchase of property and equipment	0	(303)
Net cash provided by (used in) investing activities	0	(303)
Financing activities:
Due to/from affiliate, net	(34,699)	(24,774)
Net cash (used in) provided by financing activities	(34,699)	(24,774)
Increase (decrease) in cash	(1,029)	242
Cash, beginning of period	2,100	2,361
Cash, end of period	1,071	$ 2,603
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	7,790
Investing activities:
Net cash provided by (used in) investing activities	0
Financing activities:
Due to/from affiliate, net	(6,380)
Net cash (used in) provided by financing activities	(6,380)
Increase (decrease) in cash	1,410
Cash, beginning of period	460
Cash, end of period	$ 1,870

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Amount of cash inflow (outflow) of financing activities, excluding discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) of investing activities, excluding discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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The cash outflow from advancing money to an affiliate (an entity that is related but not strictly controlled by the entity).

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