Taxes on Income (Tax Benefits) - Components of Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ (636)	$ 2,150	$ (2,112)
Foreign	3,585	5,600	10,586
State	175	528	2,635
Subtotal	3,124	8,278	11,109
Deferred:
Federal	2,158	218	(18,629)
Foreign	475	1,382	3,034
State	352	(673)	646
State	2,985	927	(14,949)
Total tax provision (benefit)	$ 6,109	$ 9,205	$ (3,840)