Supplemental Balance Sheet, Income Statement and Cash Flow Information - Accumulated Other Comp Inc (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 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	$ 16,130	$ 5,014	16,913	$ 39,343
Balance at the end of the period	3,049,235		3,049,235
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			15,323	38,869
Amounts reclassified from accumulated other comprehensive income (loss)			1,590	474
Other comprehensive income (loss), net of tax			16,913	39,343
Balance at the end of the period	4,794	(8,250)	4,794	(8,250)
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)			187	187
Other comprehensive income (loss), net of tax			187	187
Balance at the end of the period	(1,109)	(1,483)	(1,109)	(1,483)
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			584	2,049
Amounts reclassified from accumulated other comprehensive income (loss)			1,341
Other comprehensive income (loss), net of tax			1,925	2,049
Balance at the end of the period	16,160	1,735	16,160	1,735
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)			62	287
Other comprehensive income (loss), net of tax			62	287
Balance at the end of the period	(3,698)	(6,281)	(3,698)	(6,281)
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			14,739	36,820
Other comprehensive income (loss), net of tax			14,739	36,820
Balance at the end of the period	$ (6,559)	$ (2,221)	$ (6,559)	$ (2,221)