Supplemental Balance Sheet and Income Statement Information - Accumulated Other Comp Inc (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 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			(14,913)
Amounts reclassified from accumulated other comprehensive income (loss)			299
Adoption of ASU No. 2016-01			(9,144)
Other comprehensive income (loss), net of tax	$ (5,422)	$ 16,130	(23,758)	$ 16,913
Balance at the end of the period	3,063,034		3,063,034
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				15,323
Amounts reclassified from accumulated other comprehensive income (loss)				1,590
Other comprehensive income (loss), net of tax			(23,758)	16,913
Balance at the end of the period	(12,573)	4,794	(12,573)	4,794
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)			216	187
Other comprehensive income (loss), net of tax			216	187
Balance at the end of the period	(706)	(1,109)	(706)	(1,109)
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				584
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)	1,925
Balance at the end of the period		16,160		16,160
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)			83	62
Other comprehensive income (loss), net of tax			83	62
Balance at the end of the period	(4,028)	(3,698)	(4,028)	(3,698)
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			(14,913)	14,739
Other comprehensive income (loss), net of tax			(14,913)	14,739
Balance at the end of the period	$ (7,839)	$ (6,559)	$ (7,839)	$ (6,559)