Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Change in estimated fair value of investment in debt securities, tax	$ 0	$ 0	$ (74)	$ 0
Unrecognized actuarial loss and prior service costs, tax	53	235	716	1,760
Foreign currency translation adjustments, tax	0	(696)	0	(82)
Income tax on cash flow hedge activity	$ 0	$ (38)	$ (72)	$ (112)