Investments - Schedule of Summarized Financial Information, D&B (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Condensed Combined Balance Sheets
Total current assets	$ 491.4		$ 630.9
Total assets	2,705.1	$ 1,957.8	2,092.2
Current liabilities	152.1		198.7
Long-term debt	48.9		127.1
Total liabilities	500.1		562.4
Total capital	2,205.0	1,202.5	1,529.8	$ 1,199.7
Total liabilities and equity	2,705.1		2,092.2
Condensed Combined Statements of Earnings
Total revenues	1,090.3	274.9
Net earnings (loss)	638.1	(19.9)
Unconsolidated affiliates | Dun & Bradstreet
Condensed Combined Balance Sheets
Total current assets	570.1		417.9
Goodwill and other intangible assets, net	7,994.2		8,091.5
Other assets	608.1		603.4
Total assets	9,172.4		9,112.8
Current liabilities	927.7		1,090.4
Long-term debt	4,023.9		3,818.9
Other non-current liabilities	1,568.5		1,594.0
Total liabilities	6,520.1		6,503.3
Preferred equity	1,032.8		1,030.6
Total capital	1,619.5		1,578.9
Total liabilities and equity	9,172.4		$ 9,112.8
Condensed Combined Statements of Earnings
Total revenues	395.3	174.1
Loss before income taxes	(1.0)	(111.6)
Net earnings (loss)	73.9	(81.1)
Dividends attributable to preferred equity and noncontrolling interest expense	(32.4)	(18.3)
Net income (loss) attributable to Dun & Bradstreet	$ 41.5	$ (99.4)