Beginning in the second quarter of 2020, the Company took restructuring actions to lower its operating expenses structurally and permanently relative to revenue and to accelerate the transformation of our business (the “2020 Restructuring Plan”). These actions continued through the fourth quarter, and most were based on our recent experience and learning in the COVID-19 pandemic and a resulting review of our operations to address certain operating expenses such as occupancy expense and salaries and related expenses.

Lease impairment costs, which relate to the office spaces that were vacated as part of the 2020 Restructuring Plan, included impairments of operating lease right-of-use assets and associated leasehold improvements, furniture and asset retirement obligations in addition to losses and gains related to early lease terminations. Lease impairments were calculated based on estimated fair values using market participant assumptions including forecasted net discounted cash flows related to the operating lease right-of-use assets.

All restructuring actions were identified and initiated in 2020, with all actions completed by the end of the fourth quarter of 2020. The amounts for the three and nine months ended September 30, 2021 are adjustments to the actions taken in 2020.


	Three months ended September 30,				Nine months ended September 30,
	2021		2020		2021		2020
Severance and termination costs	$	(2.1)	$	17.9	$	(0.1)	$	62.5
Lease impairment costs	(3.2)		26.6		(4.2)		92.3
Other restructuring costs	1.8		2.8		1.9		5.1
Total restructuring charges	$	(3.5)	$	47.3	$	(2.4)	$	159.9

Net restructuring charges were comprised of $(0.6) at IAN, $(0.6) at DXTRA and $(2.3) at Corporate and Other for the three months ended September 30, 2021, which include non-cash lease impairment costs of $(2.1) at IAN and $(1.1) at DXTRA. Net restructuring charges were comprised of $0.0 at IAN, $(0.1) at DXTRA and $(2.3) at Corporate and Other for the nine months ended September 30, 2021, which include non-cash lease impairment costs of $(2.8) at IAN and $(1.4) at DXTRA.

Net restructuring charges were comprised of $24.9 at IAN and $17.2 at DXTRA for the three months ended September 30, 2020, which include non-cash lease impairment costs of $14.3 and $12.8, respectively. Net restructuring charges were comprised of $93.7 at IAN and $53.9 at DXTRA for the nine months ended September 30, 2020, which include non-cash lease impairment costs of $50.1 and $39.6, respectively.

A summary of the restructuring activities taken in the first nine months of 2021 related to the 2020 Restructuring Plan is as follows:


	2020 Restructuring Plan
	Liability at December 31, 2020		Restructuring Expense		Non-Cash Items		Cash Payments		Liability at September 30, 2021
Severance and termination costs	$	74.6	$	(0.1)	$	0.3	$	61.4	$	12.8
Lease impairment costs	0.0		(4.2)		(4.2)		0.0		0.0
Other restructuring costs	0.0		1.9		1.7		0.2		0.0
Total	$	74.6	$	(2.4)	$	(2.2)	$	61.6	$	12.8