The components of other intangible assets, net, as of December 31, 2021 and 2020, were as follows:

			December 31,
			2021							2020
	Weighted
	Average		Intangible					Intangible		Intangible					Intangible
	Life		Assets,		Accumulated			Assets,		Assets,		Accumulated			Assets,
(millions)	(Years)		Gross		Amortization			Net		Gross		Amortization			Net
Covenant not to compete		1.9	$	2.9	$	(2.3	)	$	0.6	$	2.9	$	(1.3	)	$	1.6
Trade names and trademarks		2.0		0.9		(0.5	)		0.4		0.9		(0.2	)		0.7
Proprietary know how		2.8		3.8		(1.3	)		2.5		3.8		(0.4	)		3.4
Management contract rights		7.2		81.0		(47.7	)		33.3		81.0		(42.6	)		38.4
Customer relationships		12.1		21.5		(3.9	)		17.6		21.5		(2.5	)		19.0
Other intangible assets, net		8.5	$	110.1	$	(55.7	)	$	54.4	$	110.1	$	(47.0	)	$	63.1

Amortization expense related to intangible assets for the years ended December 31, 2021, 2020 and 2019, which was included in Depreciation and amortization within the Consolidated Statements of Income (Loss), was as follows:

The expected future amortization of intangible assets as of December 31, 2021 was as follows:

As discussed in Note 1. Significant Accounting Policies and Practices, due to the impact of COVID-19 on the Company’s expected future operating cash flows, the Company determined certain impairment testing triggers had occurred for Proprietary know how intangible assets as of June 30, 2020.

Accordingly, the Company analyzed undiscounted cash flows for these intangible assets as of June 30, 2020 and determined the carrying value for the Proprietary know how assets was higher than their projected undiscounted cash flows. As a result, the Company recorded $3.7 million of impairment charges within the Aviation segment during the year ended December 31, 2020, which was recognized within Impairment of goodwill and intangible assets in the Consolidated Statements of Income (Loss).

Additionally, due to the termination of certain contracts within the Aviation segment during August 2020 and the impact of COVID-19 on the Company's expected future operating cash flows, the Company analyzed undiscounted cash flows for customer relationships and trade names and trademarks as of August 31, 2020. The Company determined the carrying values for certain customer relationships and trade names and trademarks were higher than their projected undiscounted cash flows. As a result, the Company recorded $72.1 million of impairment charges within the Aviation segment during the year ended December 31, 2020, which was recognized within Impairment of goodwill and intangible assets in the Consolidated Statements of Income (Loss).

The fair value of these intangible assets were classified as Level 3 in the fair value hierarchy. See Note 11. Fair Value Measurement for further discussion.

No impairment charges were recorded during the years ended December 31, 2021 and 2019.