Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Taxes on Change in unrecognized benefit plan losses arising during the period	$ 0	$ 0	$ (285)	$ 2,367
Taxes on Adjustment for previously unrecognized benefit plan gains and losses included in net income	(26)	(28)	(77)	(85)
Taxes on Change in unrealized holding gains and losses arising during the period	0	341	(60)	1,026
Taxes on Adjusted for gain on investment sale included in net income	40	0	(1,921)	0
Taxes on Change in unrealized gains and losses on cash flow hedging instrument arising during the period	(497)	0	(3,950)	0
Taxes on gains and losses on cash flow hedging instrument reclassified to net income	509		1,638	0
Taxes on Change in foreign currency translation adjustments	$ 42	$ (103)	$ 2,752	$ (1,198)