Spin-off of Apergy Corporation (Details) € in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2018 EUR (€)	May 09, 2018 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received from Apergy, net of cash distributed	$ 689,643	$ 0	$ 0
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Cash and Cash Equivalents					$ 10,400
Total current assets		417,678
Total assets	0	1,865,553
Total current liabilities		156,921
Total Liabilities	0	$ 264,253
Apergy [Member]
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Cash and Cash Equivalents					10,357
Total current assets					462,620
Non-current assets					1,438,760
Total assets					1,911,737
Total current liabilities					185,354
Non-current liabilities					119,568
Total Liabilities					304,922
Net assets distributed					1,606,815
Cash received from distribution	700,000
Net distribution					$ 906,815
Note due 2026 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Face amount of notes | €				€ 600,000
Note due 2026 [Member] | Apergy [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Face amount of notes	300,000
Debt Instrument, Unused Borrowing Capacity, Amount	$ 415,000