Supplemental Balance Sheet, Income Statement and Cash Flow Information - Accumulated Other Comp Inc (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			$ 3,247,025
Other comprehensive income (loss), net of tax	$ 10,863	$ (3,675)	27,776	$ 35,668
Balance at the end of the period	2,901,405		2,901,405
Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(12,119)	(47,593)
Other comprehensive income (loss) before reclassifications, net of tax			26,061	31,421
Amounts reclassified from accumulated other comprehensive income (loss)			1,715	4,247
Other comprehensive income (loss), net of tax			27,776	35,668
Balance at the end of the period	15,657	(11,925)	15,657	(11,925)
Gains (losses) on cash flow hedges
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(1,296)	(1,670)
Amounts reclassified from accumulated other comprehensive income (loss)			281	472
Other comprehensive income (loss), net of tax			281	472
Balance at the end of the period	(1,015)	(1,198)	(1,015)	(1,198)
Unrealized gains (losses) on available-for-sale securities.
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			14,235	(314)
Other comprehensive income (loss) before reclassifications, net of tax			(5,122)	3,551
Amounts reclassified from accumulated other comprehensive income (loss)			1,341	3,495
Other comprehensive income (loss), net of tax			(3,781)	7,046
Balance at the end of the period	10,454	6,732	10,454	6,732
Defined benefit pension plan items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(3,760)	(6,568)
Amounts reclassified from accumulated other comprehensive income (loss)			93	280
Other comprehensive income (loss), net of tax			93	280
Balance at the end of the period	(3,667)	(6,288)	(3,667)	(6,288)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period			(21,298)	(39,041)
Other comprehensive income (loss) before reclassifications, net of tax			31,183	27,870
Other comprehensive income (loss), net of tax			31,183	27,870
Balance at the end of the period	$ 9,885	$ (11,171)	$ 9,885	$ (11,171)