Goodwill and Other Intangible Assets, Net - Summary of Changes in Goodwill by Reportable Business Segment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Beginning balance	$ 10,218.9	$ 2,791.2
Acquisitions	201.7	8,271.6
Other Adjustments	15.5	(762.5)
Impairment	0.0	0.0
Foreign Currency	124.0	(81.4)
Ending balance	10,560.1	10,218.9
Live [Member] | Operating Segments [Member]
Goodwill [Line Items]
Beginning balance	3,639.9	376.9
Acquisitions	201.7	3,315.0
Other Adjustments	45.8	(28.5)
Impairment	0.0	0.0
Foreign Currency	23.4	(23.5)
Ending balance	3,910.8	3,639.9
Learn [Member] | Operating Segments [Member]
Goodwill [Line Items]
Beginning balance	2,785.4	1,359.0
Acquisitions		1,442.4
Other Adjustments	3.9
Impairment	0.0	0.0
Foreign Currency	64.9	(16.0)
Ending balance	2,854.2	2,785.4
Work [Member] | Operating Segments [Member]
Goodwill [Line Items]
Beginning balance	1,871.0	387.3
Acquisitions		1,510.7
Other Adjustments	(16.9)
Impairment	0.0	0.0
Foreign Currency	27.7	(27.0)
Ending balance	1,881.8	1,871.0
Play [Member] | Operating Segments [Member]
Goodwill [Line Items]
Beginning balance	1,161.4	174.7
Acquisitions		991.9
Other Adjustments	(7.6)
Impairment	0.0	0.0
Foreign Currency	5.5	(5.2)
Ending balance	1,159.3	1,161.4
Other [Member] | Operating Segments [Member]
Goodwill [Line Items]
Beginning balance	761.2	493.3
Acquisitions		1,011.6
Other Adjustments	(9.7)	(734.0)
Impairment	0.0	0.0
Foreign Currency	2.5	(9.7)
Ending balance	$ 754.0	$ 761.2