Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions		3 Months Ended						6 Months Ended			9 Months Ended		12 Months Ended
		Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020		Mar. 31, 2020		Jun. 30, 2021	Jun. 30, 2020		Sep. 30, 2020		Dec. 31, 2020
Cash flows provided by (used in) operating activities:
Net income (loss)		$ (50.8)		$ (174.7)	[1]			$ (74.1)	$ (100.4)	[1]
Reconciliation of net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization								302.0	267.1	[2]
Amortization of unrecognized pension loss (gain)								0.9	(0.2)	[2]
Equity-based compensation expense								14.7	28.9	[2]
Restructuring charge		10.1		7.1	[1]			15.9	11.9	[2]
Restructuring payments		(4.9)	$ (3.3)	(4.5)		$ (6.0)		(8.2)	(10.5)	[2]
Change in fair value of make-whole derivative liability								0.0	32.8
Changes in deferred income taxes								(22.5)	(43.3)	[2]
Changes in prepaid and accrued income taxes								5.6	(73.2)	[2]
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	[3]							55.8	24.8	[2]
(Increase) decrease in other current assets	[3]							66.4	(8.1)	[2]
Increase (decrease) in deferred revenue	[3]							36.0	52.7	[2]
Increase (decrease) in accounts payable	[3]							(1.7)	13.2	[2]
Increase (decrease) in accrued liabilities	[3]							(59.7)	(49.9)	[2]
Increase (decrease) in other accrued and current liabilities	[3]							(3.8)	1.9	[2]
(Increase) decrease in other long-term assets	[3]							(5.0)	(23.5)	[2]
Increase (decrease) in long-term liabilities	[3]							(44.5)	(17.1)	[2]
Net, other non-cash adjustments	[4]							14.7	20.6	[2]
Net cash provided by (used in) operating activities								292.5	127.7	[2]	$ 130.7		$ 205.0
Cash flows provided by (used in) investing activities:
Acquisitions of businesses, net of cash acquired								(617.0)	(15.8)	[2]
Cash settlements of foreign currency contracts								24.5	(0.7)	[2]
Payments for real estate purchase								(76.6)	0.0	[2]
Capital expenditures								(4.1)	(4.0)	[2]
Additions to computer software and other intangibles								(76.5)	(48.1)	[2]
Other investing activities, net								0.7	0.1	[2]
Net cash provided by (used in) investing activities								(749.0)	(68.5)	[2]	(112.3)		(133.3)
Cash flows provided by (used in) financing activities:
Payments of dividends								0.0	(64.1)	[2]
Payment of debt issuance costs								(2.6)	(0.8)	[2]
Other financing activities, net								(1.9)	(2.0)	[2]
Net cash provided by (used in) financing activities								281.4	(48.7)	[2]	196.2		188.6
Effect of exchange rate changes on cash and cash equivalents								0.4	(1.4)	[2]
Increase (decrease) in cash and cash equivalents								(174.7)	9.1	[2]
Cash and Cash Equivalents, Beginning of Period			$ 352.3			$ 84.4	[2]	352.3	84.4	[2]	$ 84.4	[2]	84.4	[2]
Cash and Cash Equivalents, End of Period		$ 177.6		$ 93.5	[2]			177.6	93.5	[2]			$ 352.3
Cash Paid for:
Income taxes payment (refund), net								(9.2)	14.6	[2]
Interest								87.5	135.7	[2]
Credit Facility
Cash flows provided by (used in) financing activities:
Proceeds from borrowings on lines of credit								55.5	404.7	[2]
Payments of borrowings on lines of credit								(55.5)	(317.2)	[2]
Term Loan Facility
Cash flows provided by (used in) financing activities:
Proceeds from borrowings on lines of credit								300.0	0.0	[2]
Payments of borrowings on lines of credit								(14.1)	(6.3)	[2]
Bridge Loan
Cash flows provided by (used in) financing activities:
Payments of borrowings on lines of credit								$ 0.0	$ (63.0)	[2]

[1] See discussion in Note 1 - Basis of Presentation for further detail regarding the elimination of the International lag reporting.

[2] See discussion in Note 1 - Basis of Presentation for further detail regarding the elimination of the International lag reporting.

[3] Net of the effect of acquisitions, see further details in Note 14.

[4] ncludes non-cash amortization of deferred debt issuance cost and discount of $9.4 million and $28.1 million for the six months ended June 30, 2021 and 2020, respectively.