Taxes on Income - Narrative (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 18, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Statutory income tax rate (as percent)		35.00%
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		$ 23,216	$ 26,212
DTA, operating loss carryforward, subject to expiration		14,600
DTA, operating loss carryforward, not subject to expiration		8,600
Foreign tax credit carryforwards		466	3,426
DTA. foreign tax credit carryforwards, subject to expiration		300
Valuation allowance		29,782	15,428	$ 18,897	$ 19,353
Unrecognized tax benefits that would impact effective tax rate		500
Income tax penalties and interest expense		300	300
Decrease in unrecognized tax benefits is reasonably possible		400
Provisional income tax expense (benefit)		2,400
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense		10,400
Transition tax for accumulated foreign earnings, provisional liability		210,600
Deferred tax liability, provisional income tax benefit		7,100
Provisional income tax expense (benefit), other		900
Underground Solutions
Operating Loss Carryforwards [Line Items]
Foreign earnings repatriated	$ 29,700
Foreign earnings repatriated, tax impact	$ 3,200
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
DTA, tax credit carryforward, not subject to expiration		200
Change in the balance of the valuation allowance for deferred tax assets allocated to income tax expense		4,598	1,364	(756)
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Change in the balance of the valuation allowance for deferred tax assets allocated to income tax expense		$ 12,755	$ (4,202)	$ 4,834