Supplemental Balance Sheet and Income Statement Information - Accumulated Other Comp Inc (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			$ 2,700,850
Adoption of ASU No. 2016-01			0
Other comprehensive income (loss), net of tax	$ (3,077)	$ 5,458	12,758	$ (18,300)
Balance at the end of the period	2,251,705		2,251,705
Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(29,325)	11,185
Other comprehensive income (loss) before reclassifications			12,314	(9,604)
Amounts reclassified from accumulated other comprehensive income (loss)			444	448
Adoption of ASU No. 2016-01				(9,144)
Other comprehensive income (loss), net of tax			12,758	(18,300)
Balance at the end of the period	(16,567)	(7,115)	(16,567)	(7,115)
Gains (losses) on cash flow hedges
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(492)
Amounts reclassified from accumulated other comprehensive income (loss)			319
Other comprehensive income (loss), net of tax			319
Balance at the end of the period	(173)		(173)
Gains (losses) on cash flow hedges.
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period				(922)
Amounts reclassified from accumulated other comprehensive income (loss)				323
Other comprehensive income (loss), net of tax				323
Balance at the end of the period		(599)		(599)
Unrealized gains (losses) on available-for-sale securities
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period				9,144
Adoption of ASU No. 2016-01				(9,144)
Other comprehensive income (loss), net of tax				(9,144)
Defined benefit pension plan items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(3,945)	(4,111)
Amounts reclassified from accumulated other comprehensive income (loss)			125	125
Other comprehensive income (loss), net of tax			125	125
Balance at the end of the period	(3,820)	(3,986)	(3,820)	(3,986)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(24,888)	7,074
Other comprehensive income (loss) before reclassifications			12,314	(9,604)
Other comprehensive income (loss), net of tax			12,314	(9,604)
Balance at the end of the period	$ (12,574)	$ (2,530)	$ (12,574)	$ (2,530)