Goodwill and Other Assets (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 1,373.1	$ 1,289.0	$ 452.2
Accumulated impairment losses	(290.7)	(290.7)	(290.7)
Beginning balance	998.3	161.5
Goodwill acquired	1.6	882.6
Goodwill adjustment	6.2	(0.5)
Currency translation adjustment	76.3	(45.3)
Ending balance	1,082.4	998.3
Services Segment [Member]
Goodwill [Line Items]
Goodwill	938.1	890.0	452.2
Accumulated impairment losses	(290.7)	(290.7)	(290.7)
Beginning balance	599.3	161.5
Goodwill acquired	1.6	459.1
Goodwill adjustment	4.1	(0.5)
Currency translation adjustment	42.4	(20.8)
Ending balance	647.4	599.3
Software Segment [Member]
Goodwill [Line Items]
Goodwill	244.9	224.9	0.0
Accumulated impairment losses	0.0	0.0	0.0
Beginning balance	224.9	0.0
Goodwill acquired	0.0	238.7
Goodwill adjustment	0.9	0.0
Currency translation adjustment	19.1	(13.8)
Ending balance	244.9	224.9
Systems Segment [Member]
Goodwill [Line Items]
Goodwill	190.1	174.1	0.0
Accumulated impairment losses	0.0	0.0	$ 0.0
Beginning balance	174.1	0.0
Goodwill acquired	0.0	184.8
Goodwill adjustment	1.2	0.0
Currency translation adjustment	14.8	(10.7)
Ending balance	$ 190.1	$ 174.1