Restructuring - Restructuring Charges By Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 17.4	$ 7.4	$ 44.7	$ 12.8
Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	96.4		96.4
Restructuring Charges	17.4	7.4	44.7	12.8
Services Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	56.6		56.6
Restructuring Charges	14.2	1.0	33.1	3.3
Software Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	8.7		8.7
Restructuring Charges	1.0	2.0	0.8	2.5
Systems Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	22.3		22.3
Restructuring Charges	1.9	0.7	5.4	1.6
Corporate, Non-Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	8.8		8.8
Restructuring Charges	0.3	3.7	5.4	5.4
DN2020 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	17.4		44.7
DN2020 Plan [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	87.5		87.5
DN2020 Plan [Member] | Services Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	54.5		54.5
DN2020 Plan [Member] | Software Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	6.8		6.8
DN2020 Plan [Member] | Systems Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	18.7		18.7
DN2020 Plan [Member] | Corporate, Non-Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	7.5		7.5
Multi-Year Transformation Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		4.3		9.7
Delta Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 3.1		$ 3.1
Delta Program [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	3.2		3.2
Delta Program [Member] | Services Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	0.1		0.1
Delta Program [Member] | Software Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	1.8		1.8
Delta Program [Member] | Systems Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	0.0		0.0
Delta Program [Member] | Corporate, Non-Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	1.3		1.3
Strategic Alliance Plan [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	5.7		5.7
Strategic Alliance Plan [Member] | Services Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	2.0		2.0
Strategic Alliance Plan [Member] | Software Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	0.1		0.1
Strategic Alliance Plan [Member] | Systems Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	3.6		3.6
Strategic Alliance Plan [Member] | Corporate, Non-Segment [Member] | Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	$ 0.0		$ 0.0