Selected Balance Sheet Data, Accounts Receivable (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Accounts Receivable, Net
Accounts receivable	$ 70.0	$ 64.7
Less allowance for bad debts	(6.0)	(5.5)
Accounts receivable, net	$ 64.0	$ 59.2

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant