Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Summary of Changes in the Allowance for Doubtful Accounts

The following table presents the changes in our allowance for doubtful accounts for the periods presented:

	December 31,
	2016			2015			2014
	(in millions)
Allowance for doubtful accounts:
Balance, beginning of period	$	6		$	7		$	3
Charges (recoveries) to earnings		4			3			3
Write-offs, net of recoveries and other    adjustments		(1	)		(4	)		1
Balance, end of period	$	9		$	6		$	7

Adoption of New Guidance Impact on Previously Reported Quarterly Results

Adoption of the new guidance resulted in the recognition of net excess tax expense and benefit in our provision for income taxes rather than additional paid-in capital.  As a result, we recorded $1 million of income tax benefit for the year ended December 31, 2016, and impacted our previously reported quarterly results for the three months ended March 31, 2016 and June 30, 2016, as follows:

	Three months ended March 31, 2016
	As Reported			As Adjusted (1)(2)
	(in millions, except per share data)
Consolidated Statement of Operations:
Operating income	$	42		$	42
Provision for income taxes		(11	)		(9	)
Net income		27			29
Basic EPS	$	0.19		$	0.20
Diluted EPS	$	0.18		$	0.20
Consolidated Statement of Cash Flows:
Net cash provided by operating activities	$	120		$	124
Net cash used in financing activities	$	(94	)	$	(98	)

	Three months ended June 30, 2016
	As Reported			As Adjusted (1)
	(in millions, except per share data)
Consolidated Statement of Operations:
Operating income	$	48		$	47
Provision for income taxes		(11	)		(10	)
Net income		34			34
Basic EPS	$	0.23		$	0.23
Diluted EPS	$	0.23		$	0.23
	Six months ended June 30, 2016
	As Reported			As Adjusted (2)
	(in millions)
Consolidated Statement of Cash Flows:
Net cash provided by operating activities	$	357		$	363
Net cash used in financing activities	$	(123	)	$	(129	)

(1)	The election to account for forfeitures as they occur did not have a material impact for the three months ended March 31, 2016 and resulted in an increase to stock-based compensation expense of approximately $1 million for the three months ended June 30, 2016.
(2)	Includes the reclassification of cash flows related to excess tax benefits from financing activities to operating activities of $4 million and $2 million for the three months ending March 31, 2016 and June 30, 2016, respectively.