Taxes on Income - Net Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets:
Foreign tax credit carryforwards	$ 466	$ 3,426
Net operating loss carryforwards	23,216	26,212
Accrued expenses	12,107	17,366
Other	4,707	8,701
Total gross deferred income tax assets	40,496	55,705
Less valuation allowance	(29,782)	(15,428)
Net deferred income tax assets	10,714	40,277
Deferred income tax liabilities:
Property, plant and equipment	(9,482)	(12,627)
Intangible assets	(2,201)	(28,346)
Undistributed foreign earnings	0	(7,051)
Other	(6,576)	(9,237)
Total deferred income tax liabilities	(18,259)	(57,261)
Net deferred income tax liabilities	$ (7,545)	$ (16,984)