Commitments and Contingencies (Narrative) (Details) $ / shares in Units, $ / Person in Thousands, $ in Thousands			4 Months Ended	6 Months Ended
	Apr. 05, 2019 USD ($)	Apr. 10, 2018 $ / shares shares	Dec. 31, 2018 USD ($) shares	Jun. 30, 2019 USD ($) $ / Person	Dec. 31, 2017 USD ($)
Commitments and Contingencies [Line Items]
Self-insured health insurance, liability				$ 232
Derivative Liability			$ 24,976	10,819	$ 37,096
Derivative Financial Instrument, Liabilities, Fair Value Disclosure, Noncurrent			11,209	9,504
Derivative Financial Instrument, Liabilities, Fair Value Disclosure, Current			13,767	$ 1,315
Maximum [Member]
Commitments and Contingencies [Line Items]
Self-insured health insurance limit, per person | $ / Person				120
Self-insured health Insurance, aggregate liability based on participants and claims (percentage)				125.00%
Self-insured health insurance, estimated cumulative liability for annual contract				$ 3,300
Contingent Accrued Earn-out Acquisition Consideration [Member]
Commitments and Contingencies [Line Items]
Derivative Liability			25,000	10,800
Contingent liability for accrued earn-out acquisition consideration			11,200	9,500
Business Combination, Contingent Consideration, Liability, Current			$ 13,800	$ 1,300
Stock Appreciation Rights (SARs) [Member] | Chief Executive Officer [Member]
Commitments and Contingencies [Line Items]
Deferred Compensation Arrangement with Individual, Shares Issued | shares		5,953,975
Deferred Compensation Arrangement With Individual, Acquisition Event, Base Price Per Share | $ / shares		$ 7.95
Settled Litigation [Member]
Commitments and Contingencies [Line Items]
Loss Contingency, Damages Sought, Legal Expenses, Value	$ 19,650
Settled Litigation [Member] | Stock Appreciation Rights (SARs) [Member] | Chief Executive Officer [Member]
Commitments and Contingencies [Line Items]
Deferred Compensation Arrangement with Individual, Acquisition Event, Involuntary Termination, Shares Deemed Accrued And Eligible To Vest | shares			1,000,000
Deferred Compensation Arrangement with Individual, Acquisition Event, Involuntary Termination, Increase On Each Anniversary, Shares Deemed Accrued And Eligible To Vest | shares			750,000