Income Taxes - Rate reconcilation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes
Income tax (benefit) expense at the statutory rate	$ (29,769)	$ 22,906	$ 36,863
Provision to return and deferred tax adjustments	(264)	1,858	145
State tax, net of federal benefit	2,181	3,584	3,504
Permanent adjustments	1,411	1,514	1,810
Tax rates (less than) in excess of statutory tax rates	(18,398)	8,161	(5,035)
Impact of Finance Structure	(5,734)	(8,165)
Gain on divestiture			3,465
Nondeductible transaction costs	6,743	3,844
Goodwill impairment	41,510
US Tax Reform	(11,569)
Stock Compensation	(2,464)
Other	(206)	316	(773)
Subtotal	(16,559)	34,018	39,979
Change in valuation allowance	7,267	(7,396)	(637)
Total income tax (benefit) expense	$ (9,292)	$ 26,622	$ 39,342

Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to increase (decrease) in income tax rate and transition tax on accumulated earnings of controlled foreign corporation deemed repatriated pursuant to Tax Cuts and Jobs Act of 2017.

No definition available.