Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ (204.1)	$ 2,737.6	$ 2,408.4
Other comprehensive income (loss):
Change in foreign currency translation gains (losses)		501.9	(436.4)	(859.8)
Change in net unrealized gains and losses on securities		(181.3)	303.0	(138.1)
Change in defined benefit pension and retiree health benefit plans (Note 14)		(576.6)	(512.8)	572.9
Change in effective portion of cash flow hedges		27.8	11.7	(42.0)
Other comprehensive income (loss) before income taxes		(228.2)	(634.5)	(467.0)
Benefit (provision) for income taxes related to other comprehensive income (loss) items		402.7	(10.6)	(121.9)
Net other comprehensive income (loss)	[1]	174.5	(645.1)	(588.9)
Comprehensive income (loss)		$ (29.6)	$ 2,092.5	$ 1,819.5

[1] Other comprehensive loss in 2016 consists of $693.3 million of other comprehensive loss attributable to controlling interest and $48.2 million of other comprehensive income attributable to non-controlling interest. Other comprehensive income in 2017 consists of $199.0 million of other comprehensive income attributable to controlling interest and $24.5 million of other comprehensive loss attributable to non-controlling interest.