Supplemental Balance Sheet and Income Statement Information - Accumulated Other Comp Inc (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			$ 2,911,816
Other comprehensive income (loss) before reclassifications			(9,604)
Amounts reclassified from accumulated other comprehensive income (loss)			448
Adoption of ASU No. 2016-01			(9,144)
Other comprehensive income (loss), net of tax	$ 5,458	$ 10,863	(18,300)	$ 27,776
Balance at the end of the period	2,931,222		2,931,222
Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			11,185	(12,119)
Other comprehensive income (loss) before reclassifications				26,061
Amounts reclassified from accumulated other comprehensive income (loss)				1,715
Other comprehensive income (loss), net of tax			(18,300)	27,776
Balance at the end of the period	(7,115)	15,657	(7,115)	15,657
Gains (losses) on cash flow hedges
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(922)	(1,296)
Amounts reclassified from accumulated other comprehensive income (loss)			323	281
Other comprehensive income (loss), net of tax			323	281
Balance at the end of the period	(599)	(1,015)	(599)	(1,015)
Unrealized gains (losses) on available-for-sale securities
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			9,144	14,235
Other comprehensive income (loss) before reclassifications				(5,122)
Amounts reclassified from accumulated other comprehensive income (loss)				1,341
Adoption of ASU No. 2016-01			(9,144)
Other comprehensive income (loss), net of tax			(9,144)	(3,781)
Balance at the end of the period		10,454		10,454
Defined benefit pension plan items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(4,111)	(3,760)
Amounts reclassified from accumulated other comprehensive income (loss)			125	93
Other comprehensive income (loss), net of tax			125	93
Balance at the end of the period	(3,986)	(3,667)	(3,986)	(3,667)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			7,074	(21,298)
Other comprehensive income (loss) before reclassifications			(9,604)	31,183
Other comprehensive income (loss), net of tax			(9,604)	31,183
Balance at the end of the period	$ (2,530)	$ 9,885	$ (2,530)	$ 9,885