Preparation of Interim Financial Statements: Impact of ASU 2016-13 Adoption (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts Receivable, before Allowance for Credit Loss		$ 575.5
Balance as of December 31, 2019	$ (47.7)	(47.7)	$ (48.2)
Accounts Receivable, after Allowance for Credit Loss, Current		$ 527.8	574.7
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	(47.7)
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	(2.6)
Provision for Loan, Lease, and Other Losses	(12.8)
Financing Receivable, Allowance for Credit Loss, Writeoff	15.9
Financing Receivable, Allowance for Credit Loss	$ (48.2)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest			(1.8)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest			$ (1.8)