Acquisitions - Additional Information (Details) $ in Millions	1 Months Ended			3 Months Ended		6 Months Ended
	Nov. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jul. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) business	Sep. 30, 2016 USD ($) business	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2016 USD ($)
Business Acquisition [Line Items]
Aggregate purchase price, net of cash acquired						$ 428.4	$ 13.3
Goodwill				$ 1,139.6		1,139.6		$ 999.3
Purchase price of intellectual property, gross		$ 95.0			$ 95.0
Cash payment to acquire intellectual property		90.0				90.0	0.0
Obligations related to the purchase of intellectual property		5.0		5.0	5.0	5.0	$ 0.0
Contingent consideration obligations		$ 40.0		$ 40.0	$ 40.0	$ 40.0
NACC
Business Acquisition [Line Items]
Aggregate purchase price in cash			$ 410.0
Aggregate purchase price, net of cash acquired			406.2
Net tangible assets acquired			61.7
Goodwill			140.4
Intangible assets			$ 204.1
M&O Systems Inc
Business Acquisition [Line Items]
Aggregate purchase price in cash	$ 22.3
Goodwill	17.0
Intangible assets	11.2
Aggregate purchase price	24.8
Note payable to seller incurred on acquisition	2.5
Net tangible liabilities assumed	$ 3.3
M&O Systems Inc | Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life of finite lived intangible assets acquired	7 years
M&O Systems Inc | Software Technology
Business Acquisition [Line Items]
Weighted average useful life of finite lived intangible assets acquired	6 years
Investor Communication Solutions
Business Acquisition [Line Items]
Number of businesses acquired | business					1
Global Technology and Operations
Business Acquisition [Line Items]
Number of businesses acquired | business				1