CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 598.2	$ 356.2	$ 1,398.9	$ 1,075.1
Other comprehensive income (loss):
Foreign currency translation adjustments	(15.5)	15.5	2.7	(7.7)
Pension liability adjustment	0.0	(1.7)	0.0	(7.6)
Net unrealized gains (losses) related to cash flow hedges:
Unrealized holding gains (losses)	30.7	(62.8)	(190.3)	344.1
Tax benefit (expense)	8.4	(31.5)	18.4	(21.6)
Unrealized holding gains (losses), net of tax	39.1	(94.3)	(171.9)	322.5
Reclassification adjustment for (gains) included in net income	(59.9)	(89.0)	(146.6)	(158.2)
Tax (benefit)	(0.6)	(0.5)	(1.3)	(1.0)
Reclassification adjustment for (gains) included in net income, net of tax	(60.5)	(89.5)	(147.9)	(159.2)
Net unrealized gains (losses) on marketable securities available for sale:
Unrealized holding gains (losses)	28.5	68.8	(353.3)	(8.3)
Tax benefit (expense)	(11.7)	(23.4)	127.3	3.1
Unrealized holding gains (losses), net of tax	16.8	45.4	(226.0)	(5.2)
Reclassification adjustment for losses included in net income	30.1	1.3	40.5	0.7
Tax (benefit)	(10.5)	(0.4)	(14.1)	(0.2)
Reclassification adjustment for losses included in net income, net of tax	19.6	0.9	26.4	0.5
Total other comprehensive income (loss)	(0.5)	(123.7)	(516.7)	143.3
Comprehensive income	$ 597.7	$ 232.5	$ 882.2	$ 1,218.4