Supplemental Financial Statement Information (Allowance for Credit on Losses for Accounts and Other Receivables) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of year	$ 18,899
Allowance for credit losses	6,382	$ 35,400
Balance at end of period	11,807
Accounts and other receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at end of period	11,807	29,669
Other assets
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at end of period	18,248	0
ASU 2016-13
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of year	35,344	17,830
Allowance for credit losses	6,388	16,856
Write-offs, recoveries and other	(11,677)	(20,353)
Balance at end of period	30,055	29,669
ASU 2016-13 | Cumulative Effect
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at end of period	$ 0	$ 15,336