Supplemental Balance Sheet and Income Statement Information - Accumulated Other Comp Inc (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	$ 1,982,811
Other comprehensive income (loss), net of tax	(17,218)	$ 9,338
Balance at the end of the period	1,555,921
Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(11,788)	(29,325)
Other comprehensive income (loss) before reclassifications	(17,365)	9,190
Amounts reclassified from accumulated other comprehensive income (loss)	147	148
Other comprehensive income (loss), net of tax	(17,218)	9,338
Balance at the end of the period	(29,006)	(19,987)
Gains (losses) on cash flow hedges
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(65)	(492)
Amounts reclassified from accumulated other comprehensive income (loss)	107	106
Other comprehensive income (loss), net of tax	107	106
Balance at the end of the period	42	(386)
Defined benefit pension plan items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(3,778)	(3,945)
Amounts reclassified from accumulated other comprehensive income (loss)	40	42
Other comprehensive income (loss), net of tax	40	42
Balance at the end of the period	(3,738)	(3,903)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(7,945)	(24,888)
Other comprehensive income (loss) before reclassifications	(17,365)	9,190
Other comprehensive income (loss), net of tax	(17,365)	9,190
Balance at the end of the period	$ (25,310)	$ (15,698)