SCHEDULE II. VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for doubtful accounts
Deductions from asset accounts:
Balance at Beginning of Period		$ 4,472	$ 10,883	$ 10,579
Additions, Charged to Expenses		2,229	720	2,830
Additions, Charged to Other Accounts	[1]	0	(70)	(7)
Deductions	[2]	1,120	7,061	2,519
Balance at End of Period		5,581	4,472	10,883
Valuation allowance for deferred tax assets
Deductions from asset accounts:
Balance at Beginning of Period		355,559	46,751	46,283
Additions, Charged to Expenses		16,668	308,808	468
Additions, Charged to Other Accounts		0	0	0
Deductions		0	0	0
Balance at End of Period		$ 372,227	$ 355,559	$ 46,751

[1] For allowance for credit losses, primarily includes amounts previously written off which were credited directly to this account when recovered.

[2] For allowance for credit losses, amounts written off as uncollectible or transferred to other accounts or utilized.