XML 30 R16.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Asset Retirement Obligations (Notes)
 12 Months Ended
Dec. 31, 2019
Asset Retirement Obligation Disclosure [Abstract]  
Asset Retirement Obligations ASSET RETIREMENT OBLIGATIONS
These accrued obligations relate to underground storage caverns, offshore platforms, pipelines, and gas transmission facilities. At the end of the useful life of each respective asset, we are legally obligated to plug storage caverns and remove any related surface equipment, to dismantle offshore platforms, to cap certain gathering pipelines at the wellhead connection and remove any related surface equipment, and to remove certain components of gas transmission facilities from the ground.
During 2019 and 2018, our overall asset retirement obligation changed as follows (in thousands): 
 
 
2019
 
2018
Beginning balance
 
$
394,323

 
$
363,956

Accretion
 
21,806

 
32,924

New obligations
 
103

 
14,162

Changes in estimates of existing obligations (1)
 
49,070

 
(8,054
)
Property dispositions/obligations settled
 
(6,093
)
 
(8,665
)
Ending balance
 
$
459,209

 
$
394,323



(1)
Changes in estimates of existing obligations are primarily due to the annual review process, which considers various factors including inflation rate, current estimates for removal costs, discount rates, and the estimated remaining life of assets. The increase in 2019 is primarily due to an increase in the inflation rate and a decrease in the discount rate. The decrease in 2018 is primarily due to a decrease in current estimates for onshore removal costs.

We are entitled to collect in rates the amounts necessary to fund our ARO. All funds received for such retirements are deposited into an external trust account dedicated to funding our ARO. Our annual funding obligation is approximately $35.9 million, with installments to be deposited monthly (See Note 6).