Note 11. Earnings Per Unit

Basic earnings per unit is computed by dividing net income or loss available to our common unitholders by the weighted-average number of our distribution-bearing units outstanding during a period. Diluted earnings per unit is computed by dividing net income or loss attributable to our limited partners by the sum of (i) the weighted-average number of our distribution-bearing units outstanding during a period (as used in determining basic earnings per unit) and (ii) the weighted-average number of our phantom units outstanding during a period.

The following table presents our calculation of basic and diluted earnings per unit for the years indicated:

	For the Year Ended December 31,
	2018			2017			2016
BASIC EARNINGS PER UNIT
Net income attributable to limited partners	$	4,172.4		$	2,799.3		$	2,513.1
Undistributed earnings allocated and cash payments on phantom unit awards (1)		(21.5	)		(15.9	)		(12.9	)
Net income available to common unitholders	$	4,150.9		$	2,783.4		$	2,500.2

Basic weighted-average number of common units outstanding		2,176.5			2,145.0			2,081.4

Basic earnings per unit	$	1.91		$	1.30		$	1.20

DILUTED EARNINGS PER UNIT
Net income attributable to limited partners	$	4,172.4		$	2,799.3		$	2,513.1

Diluted weighted-average number of units outstanding:
Distribution-bearing common units		2,176.5			2,145.0			2,081.4
Phantom units (1)		10.5			9.3			7.7
Total		2,187.0			2,154.3			2,089.1

Diluted earnings per unit	$	1.91		$	1.30		$	1.20

(1)Each phantom unit award includes a DER, which entitles the recipient to receive cash payments equal to the product of the number of phantom unit awards and the cash distribution per unit paid to our common unitholders. Cash payments made in connection with DERs are nonforfeitable. As a result, the phantom units are considered participating securities for purposes of computing basic earnings per unit.