During the year ended December 31, 2020, global restrictions on air travel and other changes in global travel patterns as a result of the COVID-19 pandemic negatively impacted short and mid-term commercial aerospace demand within our Aero/HS products end market applications. We therefore initiated a restructuring plan during the quarter ended June 30, 2020 that consisted primarily of a reduction in force measures. As the economic impact of the COVID-19 pandemic is ever evolving, we made adjustments to our estimated headcount reductions during the quarters ended September 30, 2020 and December 31, 2020 that impacted our total expected cash requirements, including recalling employees that were previously on indefinite layoff.

Employee costs related to the restructuring plan were included within Restructuring costs in our Statements of Consolidated Income and consisted of severance, voluntary buyout packages, outplacement services, estimated medical costs and associated payroll costs. Substantially all of the costs associated with the restructuring efforts initiated during the year ended December 31, 2020 were incurred and expensed as of December 31, 2020.

Cash payments associated with the restructuring plan are estimated to extend through 2022.

The following table summarizes activity relating to restructuring plan liabilities (in millions of dollars):

	Year Ended December 31, 2020
Beginning balance	$	—
Restructuring costs		12.4
Cash payments		(6.1	)
Other adjustments¹		(4.9	)
Ending balance	$	1.4

^1.

In December 2020, we revised our production forecast for 2021, thereby reducing the estimated number of headcount reductions necessary as compared with our initial restructuring plan. As such, included in Other adjustments is a reduction to our estimated restructuring liability of $4.9 million with an offset to Restructuring costs to accommodate the revised headcount requirements.