Goodwill - Changes in Carrying Amount of Goodwill by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Balance at beginning of year	$ 177.4	$ 183.9
Translation adjustments	1.2	(6.5)
Balance at end of year	178.6	177.4
Services
Goodwill [Roll Forward]
Balance at beginning of year	68.7	75.2
Translation adjustments	1.2	(6.5)
Balance at end of year	69.9	68.7
Technology
Goodwill [Roll Forward]
Balance at beginning of year	108.7	108.7
Translation adjustments	0.0	0.0
Balance at end of year	$ 108.7	$ 108.7