Accounts Receivable

12 Months Ended

Dec. 31, 2018

Receivables [Abstract]

Accounts Receivable

Accounts Receivable

The following table presents details of our accounts receivable balances:

	As of December 31,
	2018			2017
	(Dollars in millions)
Trade and purchased receivables	$	2,094		2,245
Earned and unbilled receivables	425			436
Other	21			40
Total accounts receivable	2,540			2,721
Less: allowance for doubtful accounts	(142		)	(164	)
Accounts receivable, less allowance	$	2,398		2,557

We are exposed to concentrations of credit risk from residential and business customers within our local service area, business customers outside of our local service area and from other telecommunications service providers. We generally do not require collateral to secure our receivable balances. We have agreements with other telecommunications service providers whereby we agree to bill and collect on their behalf for services rendered by those providers to our customers within our local service area. We purchase accounts receivable from other telecommunications service providers primarily on a recourse basis and include these amounts in our accounts receivable balance. We have not experienced any significant loss associated with these purchased receivables.

The following table presents details of our allowance for doubtful accounts:

	Beginning Balance		Additions	Deductions		Ending Balance
	(Dollars in millions)
2018	$	164	153	(175	)	142
2017	178		176	(190	)	164
2016	152		192	(166	)	178