General and Summary of Significant Accounting Policies Change in Accounting Estimate (Details) - USD ($) $ in Millions	Jan. 01, 2020	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Change in Accounting Estimate [Line Items]
Accounts receivable, net of allowance for doubtful accounts of $13 and $20, respectively	$ 1,479	$ 1,300	$ 1,479
Other Assets, Current	(800)	(726)	(802)
Accounts and Financing Receivable, after Allowance for Credit Loss, Noncurrent	(1,319)		(1,351)
Other Assets, Noncurrent	(1,605)	(1,660)	(1,635)	$ (1,767)
Retained Earnings (Accumulated Deficit)	(731)	(680)	(692)
Stockholders' Equity Attributable to Noncontrolling Interest	2,217	2,086	2,233
Loans and Leases Receivable, Allowance	32	0	0
Accounts Receivable, Allowance for Credit Loss, Current	20	13	20
Accounts and Financing Receivable, Allowance for Credit Loss	68	62
Other Current Assets [Member]
Change in Accounting Estimate [Line Items]
Deferred Income Tax Assets, Net	$ 165		$ 156
Mong Duong Subsidiary [Member]
Change in Accounting Estimate [Line Items]
Accounts and Financing Receivable, Allowance for Credit Loss		$ 32
Accounting Standards Update 2016-13 [Member] | Mong Duong Subsidiary [Member]
Change in Accounting Estimate [Line Items]
Financing Receivable, Credit Loss Rate	2.40%
Accounts and Financing Receivable, Allowance for Credit Loss	$ 34
Accounting Standards Update 2016-13 [Member]
Change in Accounting Estimate [Line Items]
Accounts receivable, net of allowance for doubtful accounts of $13 and $20, respectively	0
Other Assets, Current	(2)
Deferred Income Tax Assets, Net	9
Accounts and Financing Receivable, after Allowance for Credit Loss, Noncurrent	(32)
Other Assets, Noncurrent	(30)
Retained Earnings (Accumulated Deficit)	(39)
Stockholders' Equity Attributable to Noncontrolling Interest	$ (16)