NOTE 9 EARNINGS PER SHARE

We compute basic and diluted earnings per share (EPS) using the two-class method required for participating securities. Certain restricted and performance stock awards are considered participating securities when such shares have non-forfeitable dividend rights at the same rate as common stock.

Under the two-class method, undistributed earnings allocated to participating securities are subtracted from net income attributable to common stock in determining net income available to common stockholders. In loss periods, no allocation is made to participating securities because the participating securities do not share in losses. For basic EPS, the weighted-average number of common shares outstanding excludes outstanding shares related to unvested restricted stock awards. For diluted EPS, the basic shares outstanding are adjusted by adding potentially dilutive securities.

For the three and nine months ended September 30, 2017, we issued approximately 51,000 shares and 154,000 shares, respectively, of common stock in connection with our employee stock purchase plan. For the three and nine months ended September 30, 2016, we issued approximately 53,000 shares and 237,000 shares, respectively, of common stock in connection with our employee stock purchase plan.

The following table presents the calculation of basic and diluted EPS for the three and nine months ended September 30, 2017 and 2016:

	Three months ended September 30,				Nine months ended September 30,
	2017		2016(a)		2017		2016(a)
	(in millions, except per-share amounts)
Basic EPS calculation
Net (loss) income	$	(132)	$	546	$	(127)	$	356
Net income attributable to noncontrolling interest	(1)		—		(1)		—

Net (loss) income attributable to common stock	(133)		546		(128)		356
Less: net income (loss) allocated to participating securities	—		(14)		—		(7)

Net (loss) income available to common stockholders	$	(133)	$	532	$	(128)	$	349

Weighted-average common shares outstanding - basic	42.7		40.8		42.5		39.7

Basic EPS	$	(3.11)	$	13.04	$	(3.01)	$	8.79


Diluted EPS calculation
Net (loss) income	$	(132)	$	546	$	(127)	$	356
Net income attributable to noncontrolling interest	(1)		—		(1)		—

Net (loss) income attributable to common stock	(133)		546		(128)		356
Less: net income (loss) allocated to participating securities	—		(14)		—		(7)

Net (loss) income available to common stockholders	$	(133)	$	532	$	(128)	$	349


Weighted-average common shares outstanding - basic	42.7		40.8		42.5		39.7
Dilutive effect of potentially dilutive securities	—		—		—		—

Weighted-average common shares outstanding - diluted	42.7		40.8		42.5		39.7

Diluted EPS	$	(3.11)	$	13.04	$	(3.01)	$	8.79

(a)

Our previously reported basic and diluted earnings per share for the three months ended September 30, 2016 changed from $13.45 to $13.04 and $13.06 to $13.04, respectively. Our previously reported basic earnings per share for the nine months ended September 30, 2016 also changed from $8.97 to $8.79. These changes occurred because of the application of the two-class method of earnings allocation in a period with net income. Unlike other periods in 2016, the third quarter of 2016 resulted in net income because of the non-recurring gain generated from the extinguishment of debt. This represents a 3% and 2% change for the three and nine months ended September 30, 2016, respectively, from the previously reported basic earnings per share amount, which we believe is immaterial based on the absolute amount as well as the non-recurring nature of the third quarter gain, which did not affect any trends embedded in operating results.