LOSS PER SHARE

A computation of weighted average shares of common stock outstanding and loss per share for 2017, 2016 and 2015 follows:



	Year Ended December 31,
($ amounts in millions, except per share amounts)	2017			2016			2015
Net loss attributable to common stockholders	$	(296.2	)	$	(40.8	)	$	(308.6	)
Numerator adjustments for diluted loss per share:
Gain on settlement agreement related to Series B Convertible Preferred Stock	—			(103.0		)	—
Gain on amendment of Series B Convertible Preferred Stock	—			(32.9		)	—
Remeasurement adjustment associated with the Preferred Series B redemption liability	—			5.0			—
Loss allocated to PDH non-controlling interest	—			(5.9		)	—
Net loss attributable to common stockholders for diluted loss per share	$	(296.2	)	$	(177.6	)	$	(308.6	)

Basic weighted average common stock outstanding	286.1			243.3			203.2
Denominator adjustments for diluted loss per share:
Conversion related to the amendment of the Series B Convertible Preferred Stock - assumed at beginning of reporting period	—			15.3			—
Settlement of preferred stock redemption liability - assumed at beginning of reporting period	—			5.7			—
Conversion of PDH non-controlling interest	—			8.0			—
Share adjustments	—			29.0			—
Dilutive weighted average common stock outstanding	286.1			272.3			203.2

Loss per share attributable to common stockholders:
Basic	$	(1.04	)	$	(0.17	)	$	(1.52	)
Diluted	$	(1.04	)	$	(0.65	)	$	(1.52	)

Dividends per share paid to common stockholders	$	—		$	—		$	—

For 2017, 2016 and 2015, the following securities were not included in the computation of diluted shares outstanding because the effect would be anti-dilutive, or because performance targets and/or market conditions were not yet met for awards contingent upon such measures:



	Year Ended December 31,
(amounts in thousands)	2017	2016	2015
Shares issuable for the contingent consideration	7,421	8,553	4,640
Shares issuable upon conversion of PDH Common Stock	5,967	—	8,318
Shares issuable upon conversion of Series A Preferred Stock	2,000	2,000	2,000
Shares issuable upon vesting of RSUs	842	147	74
Shares issuable upon vesting and exercise of stock options	51	—	55
Shares issuable under the ESPP	3	2	1
Shares issuable upon conversion of Series B Convertible Preferred Stock	—	—	19,443
Shares contingently issuable to Founder Entities as stock dividend to Series A Preferred Stock	—	—	1,239
Total shares excluded	16,284	10,702	35,770