Goodwill (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($)
Goodwill activity:
Balance at beginning of year	$ 8,250.1
Foreign currency translation	26.1
Balance at end of year	8,276.2
Canada [Member]
Goodwill activity:
Balance at beginning of year	567.6
Foreign currency translation	5.3
Balance at end of year	572.9
Europe [Member]
Goodwill activity:
Balance at beginning of year	1,260.5
Foreign currency translation	20.5
Balance at end of year	1,281.0
MCI [Member]
Goodwill activity:
Balance at beginning of year	6.4
Foreign currency translation	0.3
Balance at end of year	6.7
UNITED STATES
Goodwill activity:
Balance at beginning of year	6,415.6
Foreign currency translation	0.0
Balance at end of year	$ 6,415.6