Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Selected Quarterly Financial Information [Abstract]
Net revenues	$ 1,239.5	$ 1,257.8	$ 1,308.9	$ 1,221.0	$ 1,385.6	$ 1,285.3	$ 1,221.3	$ 1,097.9	$ 5,027.2	$ 4,990.1	$ 4,857.8
Gross margin	751.2	772.4	801.9	746.6	857.7	799.5	756.4	690.9	3,072.1	3,104.5	3,078.6
Income before income taxes	200.2	225.8	245.2	140.6	272.1	236.6	192.2	126.5	811.8	827.4	852.2
Net income (loss)	$ (148.1)	$ 165.7	$ 179.8	$ 108.8	$ 188.9	$ 172.4	$ 140.0	$ 91.4	$ 306.2	$ 592.7	$ 633.7
Basic (in dollars per share)	$ (0.40)	$ 0.44	$ 0.47	$ 0.29	$ 0.50	$ 0.45	$ 0.37	$ 0.24	$ 0.81	$ 1.55	$ 1.62
Diluted (in dollars per share)	$ (0.40)	$ 0.43	$ 0.47	$ 0.28	$ 0.49	$ 0.45	$ 0.36	$ 0.23	$ 0.80	$ 1.53	$ 1.59
Provisional income tax change	$ 289.5								$ 289.5
Restructuring charges (benefits)	$ 36.2								$ 65.6	$ 3.3	$ (0.6)