Goodwill (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Aug. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Oct. 31, 2014
Changes in carrying amounts of goodwill
Balance at the beginning of the period		$ 432.9	$ 439.4
Goodwill acquired			0.2
Foreign currency translation		(0.7)	(0.5)
Disposals		(0.9)	(6.2)
Balance at the end of the period		431.3	432.9
Interest acquired (as a percent)				30.00%
Region Two
Changes in carrying amounts of goodwill
Disposals	$ 0.9
Operating segment | Region One
Changes in carrying amounts of goodwill
Balance at the beginning of the period		161.2	163.8
Goodwill acquired			0.0
Foreign currency translation		(0.7)	(0.5)
Disposals		0.0	(2.1)
Balance at the end of the period		160.5	161.2
Operating segment | Region Two
Changes in carrying amounts of goodwill
Balance at the beginning of the period		141.5	143.8
Goodwill acquired			0.0
Foreign currency translation		0.0	0.0
Disposals		(0.9)	(2.3)
Balance at the end of the period		140.6	141.5
Operating segment | Region Three
Changes in carrying amounts of goodwill
Balance at the beginning of the period		36.4	37.0
Goodwill acquired			$ 0.0
Foreign currency translation		0.0
Disposals		0.0	$ (0.6)
Balance at the end of the period		36.4	36.4
Operating segment | Region Four
Changes in carrying amounts of goodwill
Balance at the beginning of the period		62.7	62.6
Goodwill acquired			0.2
Foreign currency translation		0.0	0.0
Disposals		0.0	(0.1)
Balance at the end of the period		62.7	62.7
Operating segment | Region Five
Changes in carrying amounts of goodwill
Balance at the beginning of the period		31.1	32.2
Goodwill acquired			0.0
Foreign currency translation		0.0	0.0
Disposals		0.0	(1.1)
Balance at the end of the period		$ 31.1	$ 31.1