Accounts Receivable

12 Months Ended

Dec. 31, 2015

Receivables [Abstract]

Accounts Receivable

Accounts Receivable

The following table presents details of our accounts receivable balances:

	As of December 31,
	2015			2014
	(Dollars in millions)
Trade and purchased receivables	$	1,789		1,821
Earned and unbilled receivables	288			307
Other	18			22
Total accounts receivable	2,095			2,150
Less: allowance for doubtful accounts	(152		)	(162	)
Accounts receivable, less allowance	$	1,943		1,988

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)
2015	$	162	177	(187	)	152
2014	$	155	159	(152	)	162
2013	$	158	152	(155	)	155