	March 31, 2019		December 31, 2018
Asset retirement obligations	$	63.9	$	55.5
Deferred revenue		174.6		175.5
Operating lease liabilities		47.8		—
Other liabilities		14.9		31.2
Total long-term liabilities	$	301.2	$	262.2

Our asset retirement obligations (“ARO”) primarily relate to certain gas gathering pipelines, processing facilities and transportation assets.

We have certain long-term contractual arrangements for which we have received consideration that we are not yet able to recognize as revenue. The resulting deferred revenue will be recognized once all conditions for revenue recognition have been met.

Deferred revenue includes $129.0 million of payments received from Vitol Americas Corp. (“Vitol”) (formerly known as Noble Americas Corp.), a subsidiary of Vitol US Holding Co., in 2016, 2017, and 2018 as part of an agreement (the “Splitter Agreement”) related to the construction and operation of a crude oil and condensate splitter. In December 2018, Vitol elected to terminate the Splitter Agreement. The Splitter Agreement provides that the first three annual payments are ours if Vitol elects to terminate, which Vitol disputes. The timing of revenue recognition related to the Splitter Agreement deferred revenue is currently dependent upon resolution of the dispute with Vitol. Deferred revenue also includes nonmonetary consideration received in a 2015 amendment to a gas gathering and processing agreement and consideration received for other construction activities of facilities connected to our systems.

Balance at December 31, 2018	$	175.5
Additions		—
Revenue recognized		(0.9	)
Balance at March 31, 2019	$	174.6