CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	Class A ordinary shares/ Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Treasury shares [Member]	Accumulated other comprehensive income (loss) [Member]
Balance at Dec. 31, 2014	$ 4,691.4	$ 15.6	$ 1,436.9	$ 3,467.0	$ (8.0)	$ (220.1)
Balance (in shares) at Dec. 31, 2014		124.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net shares issued (acquired) under share-based compensation plans	(3.5)	$ 0.1	0.4		(4.0)
Net shares issued (acquired) under share-based compensation plans (in shares)		0.2
Share-based compensation	18.3		18.3
Excess tax benefit (deficit) from share-based compensation plans	(2.5)		(2.5)
Retirement benefit adjustments, net of taxes	10.2					10.2
Dividends	(37.9)			(37.9)
Net income (loss)	(31.0)			(31.0)
Balance at Sep. 30, 2015	4,645.0	$ 15.7	1,453.1	3,398.1	(12.0)	(209.9)
Balance (in shares) at Sep. 30, 2015		124.8
Balance at Dec. 31, 2015	4,772.5	$ 15.7	1,458.5	3,509.8	(12.2)	(199.3)
Balance (in shares) at Dec. 31, 2015		124.8
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net shares issued (acquired) under share-based compensation plans	(4.4)	$ 0.0	(9.5)		5.1
Net shares issued (acquired) under share-based compensation plans (in shares)		0.6
Share-based compensation	16.3		16.3
Excess tax benefit (deficit) from share-based compensation plans	2.6		2.6
Retirement benefit adjustments, net of taxes	25.2					25.2
Net income (loss)	345.0			345.0
Balance at Sep. 30, 2016	$ 5,157.2	$ 15.7	$ 1,467.9	$ 3,854.8	$ (7.1)	$ (174.1)
Balance (in shares) at Sep. 30, 2016		125.4