Supplemental Balance Sheet, Income Statement and Cash Flow Information - Accumulated Other Comp Inc (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	$ 4,282,710
Other comprehensive income (loss), net of tax	35,474	$ (125,115)	$ (138,618)
Balance at the end of the period	3,247,025	4,282,710
Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(47,593)	77,522
Other comprehensive income (loss) before reclassifications, net of tax	28,797	(131,549)
Amounts reclassified from accumulated other comprehensive income (loss)	6,677	6,434
Other comprehensive income (loss), net of tax	35,474	(125,115)
Balance at the end of the period	(12,119)	(47,593)	77,522
Gains (losses) on cash flow hedges
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(1,670)	(2,044)
Amounts reclassified from accumulated other comprehensive income (loss)	374	374
Other comprehensive income (loss), net of tax	374	374
Balance at the end of the period	(1,296)	(1,670)	(2,044)
Unrealized gains (losses) on available-for-sale securities.
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(314)	14,996
Other comprehensive income (loss) before reclassifications, net of tax	11,054	(15,310)
Amounts reclassified from accumulated other comprehensive income (loss)	3,495
Other comprehensive income (loss), net of tax	14,549	(15,310)
Balance at the end of the period	14,235	(314)	14,996
Defined benefit pension plan items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(6,568)	(7,263)
Amounts reclassified from accumulated other comprehensive income (loss)	2,808	695
Other comprehensive income (loss), net of tax	2,808	695
Balance at the end of the period	(3,760)	(6,568)	(7,263)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(39,041)	71,833
Other comprehensive income (loss) before reclassifications, net of tax	17,743	(116,239)
Amounts reclassified from accumulated other comprehensive income (loss)		5,365
Other comprehensive income (loss), net of tax	17,743	(110,874)
Balance at the end of the period	$ (21,298)	$ (39,041)	$ 71,833