EARNINGS PER SHARE

Earnings per share is calculated based on income from continuing and discontinued operations less any income attributable to noncontrolling interests. Income attributable to noncontrolling interests represented third-party limited partner unitholders' interests in the earnings of our consolidated subsidiary, Rose Rock, prior to completion of the Merger. Rose Rock allocated net income to its limited partners based on the distributions pertaining to the current period's available cash as defined by Rose Rock's partnership agreement. After adjusting for the appropriate period's distributions, the remaining undistributed earnings or excess distributions over earnings, if any, were allocated to Rose Rock's general partner, limited partners and participating securities in accordance with the contractual terms of Rose Rock's partnership agreement and as further prescribed under the two-class method. Incentive distribution rights did not participate in undistributed earnings. Subsequent to the Merger, there is no longer a noncontrolling interest.

Basic earnings (loss) per share is calculated based on the weighted average shares outstanding during the period. Diluted earnings (loss) per share includes the dilutive effect of unvested equity compensation awards.

The following summarizes the calculation of basic earnings per share for the years ended December 31, 2017, 2016 and 2015 (in thousands, except per share amounts):



	Year Ended December 31, 2017
	Continuing Operations			Discontinued Operations		Net
Loss	$	(17,150	)	$	—	$	(17,150	)
less: Income attributable to noncontrolling interest	—			—		—
Loss attributable to SemGroup	$	(17,150	)	$	—	$	(17,150	)
Weighted average common stock outstanding	71,418			71,418		71,418
Basic loss per share	$	(0.24	)	$	0.00	$	(0.24	)



	Year Ended December 31, 2016
	Continuing Operations		Discontinued Operations			Net
Income	$	13,263	$	(1	)	$	13,262
less: Income attributable to noncontrolling interest	11,167		—			11,167
Income attributable to SemGroup	$	2,096	$	(1	)	$	2,095
Weighted average common stock outstanding	51,889		51,889			51,889
Basic earnings per share	$	0.04	$	0.00		$	0.04



	Year Ended December 31, 2015
	Continuing Operations		Discontinued Operations			Net
Income	$	42,816	$	(4	)	$	42,812
less: Income attributable to noncontrolling interest	12,492		—			12,492
Income attributable to SemGroup	$	30,324	$	(4	)	$	30,320
Weighted average common stock outstanding	43,787		43,787			43,787
Basic earnings per share	$	0.69	$	0.00		$	0.69

The following summarizes the calculation of diluted earnings per share for the years ended December 31, 2017, 2016 and 2015 (in thousands, except per share amounts):



	Year Ended December 31, 2017
	Continuing Operations			Discontinued Operations		Net
Loss	$	(17,150	)	$	—	$	(17,150	)
less: Income attributable to noncontrolling interest	—			—		—
Loss attributable to SemGroup	$	(17,150	)	$	—	$	(17,150	)
Weighted average common stock outstanding	71,418			71,418		71,418
Effect of dilutive securities	—			—		—
Diluted weighted average common stock outstanding	71,418			71,418		71,418
Diluted loss per share	$	(0.24	)	$	0.00	$	(0.24	)



	Year Ended December 31, 2016
	Continuing Operations		Discontinued Operations			Net
Income	$	13,263	$	(1	)	$	13,262
less: Income attributable to noncontrolling interest	11,167		—			11,167
Income attributable to SemGroup	$	2,096	$	(1	)	$	2,095
Weighted average common stock outstanding	51,889		51,889			51,889
Effect of dilutive securities	392		392			392
Diluted weighted average common stock outstanding	52,281		52,281			52,281
Diluted earnings per share	$	0.04	$	0.00		$	0.04



	Year Ended December 31, 2015
	Continuing Operations		Discontinued Operations			Net
Income	$	42,816	$	(4	)	$	42,812
less: Income attributable to noncontrolling interest	12,492		—			12,492
Income attributable to SemGroup	$	30,324	$	(4	)	$	30,320
Weighted average common stock outstanding	43,787		43,787			43,787
Effect of dilutive securities	183		183			183
Diluted weighted average common stock outstanding	43,970		43,970			43,970
Diluted earnings per share	$	0.69	$	0.00		$	0.69

For the year ended December 31, 2017, we experienced net losses attributable to SemGroup. The unvested equity compensation awards would have been antidilutive and, therefore, were not included in the computation of diluted earnings per share.