REVENUE REVENUE (Tables)

9 Months Ended

Sep. 30, 2019

Revenue from Contract with Customer [Abstract]

Contract with Customer, Asset and Liability [Table Text Block]

The following tables set forth the balances in contract assets and contract liabilities for the periods indicated:

Contract Assets	(Millions of dollars)
Balance at December 31, 2018 (a)	$	6.2
Amounts invoiced in excess of revenue recognized	(0.9		)
Net additions	0.8
Balance at September 30, 2019 (b)	$	6.1

(a) - Contract assets of $1.7 million and $4.5 million are included in other current assets and other assets, respectively, in our Consolidated Balance Sheets.

(b) - Contract assets of $2.4 million and $3.7 million are included in other current assets and other assets, respectively, in our Consolidated Balance Sheets.

Contract Liabilities	(Millions of dollars)
Balance at December 31, 2018 (a)	$	31.7
Revenue recognized included in beginning balance	(15.2		)
Net additions	28.9
Balance at September 30, 2019 (b)	$	45.4

(a) - Contract liabilities of $15.6 million and $16.1 million are included in other current liabilities and other deferred credits, respectively, in our Consolidated Balance Sheets.

(b) - Contract liabilities of $25.2 million and $20.2 million are included in other current liabilities and other deferred credits, respectively, in our Consolidated Balance Sheets.

Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]

The following table presents aggregate value allocated to unsatisfied performance obligations as of September 30, 2019, and the amounts we expect to recognize in revenue in future periods, related primarily to firm transportation and storage contracts with remaining contract terms ranging from one month to 24 years:

Expected Period of Recognition in Revenue	(Millions of dollars)
Remainder of 2019	$	101.5
2020	335.6
2021	286.3
2022	228.3
2023 and beyond	952.5
Total estimated transaction price allocated to unsatisfied performance obligations	$	1,904.2