RECEIVABLES

12 Months Ended

Dec. 31, 2020

Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]

5. RECEIVABLES

Receivables include current notes, amounts billed to customers, claims, other receivables, and unbilled revenue on long-term contracts, which consists of amounts recognized as sales but not billed. Substantially all amounts of unbilled receivables are expected to be billed and collected in the subsequent year. An immaterial amount of unbilled receivables are subject to retainage provisions. The amount of claims and unapproved change orders within our receivables balances are immaterial.

The Corporation is either a prime contractor or subcontractor to various agencies of the U.S. Government. Revenues derived directly and indirectly from government sources (primarily the U.S. Government) were 53% and 43% of total net sales in 2020 and 2019, respectively. Total receivables due from government sources (primarily the U.S Government) were $352.7 million and $343.5 million as of December 31, 2020 and 2019, respectively. Government (primarily the U.S. Government) unbilled receivables, net of progress payments, were $198.6 million and $195.7 million as of December 31, 2020 and 2019, respectively.

The composition of receivables as of December 31 is as follows:


(In thousands)	2020		2019
Billed receivables:
Trade and other receivables	$	361,460	$	418,968
Unbilled receivables:
Recoverable costs and estimated earnings not billed	238,309		231,067
Less: Progress payments applied	(3,291)		(9,108)
Net unbilled receivables	235,018		221,959
Less: Allowance for doubtful accounts	(7,760)		(8,733)
Receivables, net	$	588,718	$	632,194