Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2016

Receivables [Abstract]

Schedule of the entity's accounts receivable balances

The following table presents details of our accounts receivable balances:

	As of December 31,
	2016			2015
	(Dollars in millions)
Trade and purchased receivables	$	634		620
Earned and unbilled receivables	115			111
Other	4			4
Total accounts receivable	753			735
Less: allowance for doubtful accounts	(53		)	(47	)
Accounts receivable, less allowance	$	700		688

Schedule of the entity's allowance for doubtful accounts

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

	Beginning Balance		Additions	Deductions		Ending Balance
	(Dollars in millions)
2016	$	47	80	(74	)	53
2015	$	38	78	(69	)	47
2014	$	43	64	(69	)	38