Contract Balances (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2020

Dec. 31, 2019

Contract Balances

Valuation and Qualifying Accounts

Allowance for credit losses	Balance at Beginning of Period		Current Period Provision for Expected Credit Losses		Write-offs Charged Against Allowance		Balance at End of Period
	(In thousands)
For the six months ended June 30, 2020	$	19,280	$	51,808	$	(29,900)	$	41,188

Allowance for doubtful accounts	Balance at Beginning of Year		Charged to Costs and Expenses		Deductions		Balance at End of Year
	(In thousands)
For the years ended:
December 31, 2019	$	16,956	$	69,866	$	(67,542)	$	19,280
December 31, 2018	$	15,056	$	98,461	$	(96,561)	$	16,956
December 31, 2017	$	17,440	$	124,143	$	(126,527)	$	15,056

Schedule of Contract balances

	Contract
	Liabilities
	(In thousands)
Balance as of December 31, 2019	$	609,054
Recognition of unearned revenue		(2,951,822)
Deferral of revenue		2,925,648
Balance as of June 30, 2020	$	582,880

	Contract
	Liabilities
	(In thousands)
Balance as of December 31, 2018	$	624,626
Recognition of unearned revenue		(7,086,252)
Deferral of revenue		7,070,680
Balance as of December 31, 2019	$	609,054