Accumulated Other Comprehensive Income (Loss), Net of Tax (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Balance at the beginning of the period	$ (90,834)
Balance at the end of the period	(79,717)
Foreign Currency Translation Adjustments
Balance at the beginning of the period	(84,675)
Other comprehensive income (loss) before reclassifications	23,971
Balance at the end of the period	(60,704)
Gains (Losses) on Foreign Exchange Derivative Instruments
Balance at the beginning of the period	10,535
Other comprehensive income (loss) before reclassifications	(15,727)
Amounts reclassified from accumulated other comprehensive loss	(1,962)
Tax benefit (expense)	4,395
Balance at the end of the period	(2,759)
Gains (Losses) on Available- for-Sale Securities
Balance at the beginning of the period	1,536
Other comprehensive income (loss) before reclassifications	195
Tax benefit (expense)	18
Balance at the end of the period	1,749
Pension and Other Postretirement Adjustments
Balance at the beginning of the period	(18,230)
Other comprehensive income (loss) before reclassifications	(796)
Amounts reclassified from accumulated other comprehensive loss	1,193
Tax benefit (expense)	(170)
Balance at the end of the period	(18,003)
Accumulated Other Comprehensive Loss
Balance at the beginning of the period	(90,834)
Other comprehensive income (loss) before reclassifications	7,643
Amounts reclassified from accumulated other comprehensive loss	(769)
Tax benefit (expense)	4,243
Balance at the end of the period	$ (79,717)