Spin-off of Apergy Corporation Spin-off of Apergy Corporation (Detail) € in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 EUR (€)	Dec. 31, 2017 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
TransferOfCashAndCashEquivalentsAtSpinOffNet	$ 689,643	$ 0
Separation of Apergy	(906,815)
Cash and Cash Equivalents	10,400
Current assets				$ 417,678
Total assets of discontinued operations	0			1,865,553
Current liabilities				156,921
Total liabilities of discontinued operations	0			$ 264,253
Net assets distributed to Apergy Corporation	1,606,815
Cash Dividends Paid to Parent Company	700,000
StockRepurchaseProgramNumberOfSharesPlannedToBeRepurchased	1,000,000
Net distribution to Apergy Corporation	906,815
Apergy [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt Instrument, Unused Borrowing Capacity, Amount	415,000
Cash and Cash Equivalents	10,357
Current assets	462,620
Non-current assets	1,438,760
Total assets of discontinued operations	1,911,737
Current liabilities	185,354
Noncurrent liabilities	119,568
Total liabilities of discontinued operations	$ 304,922
Note due 2026 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt Instrument, Face Amount | €			€ 702,206
Debt Instrument, Interest Rate, Stated Percentage	1.25%		1.25%
Note due 2026 [Member] | Apergy [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt Instrument, Face Amount	$ 300,000
Debt Instrument, Interest Rate, Stated Percentage	6.375%		6.375%