CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 1,999.9	$ 1,449.9	$ 1,456.2
Other comprehensive income (loss):
Foreign currency translation adjustments	(49.8)	27.4	25.9
Pension liability adjustment	(8.6)	3.2	(4.7)
Change in functional currency of a foreign subsidiary	0	0	13.1
Net asset transfer of a common control foreign subsidiary	0	0	0.6
Net unrealized gains (losses) related to cash flow hedges:
Unrealized holding gains (losses)	568.1	(3.2)	39.2
Tax (expense) benefit	12.3	(2.6)	13.8
Unrealized holding gains (losses), net of tax	580.4	(5.8)	53.0
Reclassification adjustment for (gains) included in net income	(23.1)	(7.3)	(79.6)
Tax expense (benefit)	(1.7)	(6.9)	1.9
Reclassification adjustment for (gains) losses included in net income, net of tax	(24.8)	(14.2)	(77.7)
Net unrealized gains (losses) on marketable securities available for sale:
Unrealized holding gains (losses)	494.0	205.1	1.3
Tax (expense) benefit	(173.9)	(77.1)	0.1
Unrealized holding gains (losses), net of tax	320.1	128.0	1.4
Reclassification adjustment for losses included in net income	5.4	7.3	1.1
Tax (benefit)	(1.9)	(2.2)	(0.1)
Reclassification adjustment for losses included in net income, net of tax	3.5	5.1	1.0
Total other comprehensive income	820.8	143.7	12.6
Comprehensive income	$ 2,820.7	$ 1,593.6	$ 1,468.8