Accounts Receivable, Accounts Payable and Accrued Liabilities (Tables)

12 Months Ended

Dec. 31, 2019

Accounts Receivable Accounts Payable And Accrued Liabilities [Abstract]

Schedule of Accounts Receivable

Accounts receivable consist of the following:

	As of December 31
(in thousands)	2019		2018
Receivables from contracts with customers, less doubtful accounts of $14,276 and $14,775	$	595,321	$	538,021
Other receivables	28,895		44,259
	$	624,216	$	582,280

Schedule of Changes in Allowance for Doubtful Accounts

The changes in allowance for doubtful accounts was as follows:

(in thousands)	Balance at Beginning of Period		Additions – Charged to Costs and Expenses		Deductions			Balance at End of Period
2019	$	14,775	$	1,706	$	(2,205	)	$	14,276
2018	$	22,975	$	10,209	$	(18,409	)	$	14,775
2017	$	26,723	$	33,830	$	(37,578	)	$	22,975

Schedule of Accounts Payable and Accrued Liabilities

Accounts payable and accrued liabilities consist of the following:

	As of December 31
(in thousands)	2019		2018
Accounts payable and accrued liabilities	$	366,963	$	337,123
Accrued compensation and related benefits	140,738		149,455
	$	507,701	$	486,578