Revenue (Tables)

12 Months Ended

Dec. 31, 2021

Revenue from Contract with Customer [Abstract]

Accounts Receivable and Current and Long-Term Contract Assets and Liabilities

The Company’s Accounts receivable and current and long-term contract assets and liabilities are summarized in the following table.

	Accounts Receivable, Less Allowance		Contract Assets (Current)		Contract Assets (Long-Term)		Contract Liabilities (Current)		Contract Liabilities (Long-Term)
Balance sheet caption:	Accounts receivable		Other current assets		Other assets		Other accruals		Other liabilities
Balance at December 31, 2020	$	2,078.1	$	52.0	$	170.7	$	266.3	$	8.2
Balance at December 31, 2021	2,352.4		60.9		131.2		259.8		9.2

Schedule of Allowance for Doubtful Accounts

The following table summarizes the movement in the Company’s allowance for doubtful accounts:

	2021		2020		2019
Beginning balance	$	53.5	$	36.5	$	45.9
Adjustment upon adoption of ASU 2016-13(1)			3.0
Bad debt expense	33.8		56.8		53.1
Uncollectible accounts written off, net of recoveries	(38.4)		(42.8)		(62.5)
Ending balance	$	48.9	$	53.5	$	36.5

(1)The Company adopted ASU 2016-13 effective January 1, 2020, using the modified retrospective transition method, electing to not restate prior periods. Refer to Note 1 for additional detail.