At December 31, 2018 and 2017, our regulated utility operations had recorded the following regulatory assets and liabilities included in our consolidated balance sheets. These assets and liabilities will be recognized as revenues and expenses in future periods as they are reflected in customers’ rates.



	As of December 31,
	2018		2017
(in thousands)
Regulatory Assets
Under-recovered purchased fuel and conservation cost recovery ⁽¹⁾	$	4,631	$	9,869
Under-recovered GRIP revenue ⁽²⁾	165		164
Deferred postretirement benefits ⁽³⁾	15,517		15,498
Deferred conversion and development costs ⁽¹⁾	16,727		11,735
Environmental regulatory assets and expenditures ⁽⁴⁾	2,731		3,222
Acquisition adjustment ⁽⁵⁾	33,255		39,992
Loss on reacquired debt ⁽⁶⁾	942		1,031
Other	3,250		4,994
Total Regulatory Assets	$	77,218	$	86,505


Regulatory Liabilities
Self-insurance ⁽⁷⁾	$	947	$	1,013
Over-recovered purchased fuel and conservation cost recovery ⁽¹⁾	5,443		2,048
Over-recovered GRIP revenue ⁽²⁾	1,563		2,245
Storm reserve ⁽⁷⁾	677		669
Accrued asset removal cost ⁽⁸⁾	42,401		40,948
Deferred income taxes due to rate change ⁽⁹⁾	91,162		98,492
Other	729		2,048
Total Regulatory Liabilities	$	142,922	$	147,463

⁽¹⁾ We are allowed to recover the asset or are required to pay the liability in rates. We do not earn an overall rate of return on these assets.

⁽²⁾ The Florida PSC allowed us to recover through a surcharge, capital and other program-related-costs, inclusive of an appropriate return on investment, associated with accelerating the replacement of qualifying distribution mains and services (defined as any material other than coated steel or plastic) in FPU’s natural gas distribution, Fort Meade division and Chesapeake Utilities’ Central Florida Gas division. We are allowed to recover the asset or are required to pay the liability in rates related to GRIP.

⁽³⁾ The Florida PSC allowed FPU to treat as a regulatory asset the portion of the unrecognized costs pursuant to ASC Topic 715, Compensation - Retirement Benefits, related to its regulated operations. See Note 17, Employee Benefit Plans, for additional information.

⁽⁴⁾ All of our environmental expenditures incurred to date and our current estimate of future environmental expenditures have been approved by various PSCs for recovery. See Note 20, Environmental Commitments and Contingencies, for additional information on our environmental contingencies.

⁽⁵⁾We are allowed to include the premiums paid in various natural gas utility acquisitions in Florida in our rate bases and recover them over a specific time period pursuant to the Florida PSC approvals. Included in these amounts are $543,000 of the premium paid by FPU, $34.2 million of the premium paid by us in 2009, including a gross up for income tax, because it is not tax deductible, and $746,000 of the premium paid by FPU in 2010.

⁽⁶⁾ Gains and losses resulting from the reacquisition of long-term debt are amortized over future periods as adjustments to interest expense in accordance with established regulatory practice.

⁽⁷⁾ We have self-insurance and storm reserves in our Florida regulated energy operations that allow us to collect through rates amounts to be used against general claims, storm restoration costs and other losses as they are incurred.

⁽⁸⁾ See Note 1, Summary of Significant Accounting Policies, for additional information on our asset removal cost policies.

⁽⁹⁾We recorded a regulatory liability for our regulated businesses related to the revaluation of accumulated deferred tax assets/liabilities as a result of the TCJA. Based upon the regulatory proceedings, we will pass back the respective portion of the excess accumulated deferred taxes to rate payers. See Note 12, Income Taxes, for additional information.