Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Cash flows from operating activities:
Net Income	$ (97,751)	$ (26,999)	$ (41,561)	$ (23,643)	$ (266,699)	$ (107,159)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization					46,365	28,358
Change in fair value of preferred stock					0	70,451
Amortization of preferred stock issuance costs					0	1,120
Loss on disposal of property and equipment					516	1,853
Share-based compensation					7,876	1,392
Loss on debt restructuring	0		0		2,270	0
Provision for bad debts					2,932	2,275
Deferred tax benefit					(1,332)	(9,041)
Impairment charges					158,923	0
Changes in:
Accounts receivable					47,945	34,556
Income tax receivable					1,635	3,557
Prepaid expenses and other assets					20,760	(13,754)
Accounts payable					(32,835)	(12,453)
Accrued expenses and other liabilities					(31,097)	(3,138)
Net cash used in operating activities					(42,741)	(1,983)
Cash flows from investing activities:
Capital expenditures					(20,387)	(16,922)
Proceeds from sale of property and equipment					3,281	1,316
Net cash used in investing activities					(17,106)	(15,606)
Cash flows from financing activities:
Borrowings under revolving credit facilities					540,978	60,746
Payments under revolving credit facilities					(526,643)	(85,655)
Term debt borrowings					52,592	557
Term debt payments					(40,724)	(16,285)
Debt issuance costs					(2,029)	0
Payments of debt extinguishment costs					(693)	0
Proceeds from issuance of common stock					450,000	0
Common stock issuance costs					(10,514)	0	$ (1,500)
Proceeds from issuance of preferred stock					0	34,999
Preferred stock issuance costs					0	(1,120)
Preferred stock payments					(402,884)	0
Issuance of restricted stock units, net of taxes paid					(183)	(81)
Proceeds from insurance premium financing					20,735	17,782
Payments on insurance premium financing					(12,221)	(6,252)
Payments of finance lease obligation						(2,785)
Payments of finance lease obligation					(13,921)
Net cash provided by financing activities					54,493	1,906
Net decrease in cash and cash equivalents					(5,354)	(15,683)
Cash and cash equivalents:
Beginning of period		$ 11,179		$ 25,702	11,179	25,702	25,702
End of period	$ 5,825		$ 10,019		5,825	10,019	$ 11,179
Supplemental cash flow information:
Cash paid for interest					12,933	7,436
Cash refunds from income taxes, net					(857)	(1,329)
Non-cash capital leases and other obligations to acquire assets					55,742	23,233
Capital expenditures, not yet paid					$ 2,219	$ 1,877