Credit Losses (Tables)

3 Months Ended

Mar. 31, 2020

Accounts Receivable, Allowance for Credit Loss

The following table summarizes the changes in allowance for credit losses on our accounts receivables, certain non-trade accounts receivable and contract assets for the three months ended March 31, 2020 (in thousands):



	For the Three Months Ended March 31, 2020
Beginning balance as of December 31, 2019	$	(41	)
Cumulative transition adjustment	(2,815		)
Provision for credit losses	(1,001		)
Recoveries	447
Ending balance as of March 31, 2020	$	(3,410	)

Held-to-Maturity Securities, Amortized Cost and Interest Income

The amortized cost of our investments as of March 31, 2020 and December 31, 2019 (in thousands) and interest income for the three months ended March 31, 2020 and 2019 were as follows:



	Amortized Cost				Interest Income for the Three Months Ended March 31,
	March 31, 2020		December 31, 2019		2020		2019
U.S. Treasury bills	$	10,785	$	10,784	$	65	$	58
Corporate bonds	1,705		1,705		15		9
Collateralized mortgage obligations	6,192		5,472		53		12
Yankees	597		597		5		5
Total investments	$	19,279	$	18,558	$	138	$	84