Investment in joint venture as of December 31, 2020 and 2019 reflected the equity interest in our 50% investment in our WAVE joint venture. The WAVE joint venture is reflected within the Mineral Fiber segment in our consolidated financial statements using the equity method of accounting.

We use the cumulative earnings approach to determine the appropriate classification of distributions from WAVE within our cash flow statement. During 2020, 2019 and 2018, WAVE distributed amounts in excess of our capital contributions and proportionate share of retained earnings. Accordingly, the distributions in these years were reflected as a return of investment in cash flows from investing activity in our Consolidated Statement of Cash Flows. Distributions from WAVE in 2020, 2019 and 2018, were $81.5 million, $85.2 million, and $141.7 million, respectively.

In certain markets, we sell WAVE products directly to customers pursuant to specific terms of sale. In those circumstances, we record the sales and associated costs within our consolidated financial statements. The total sales associated with these transactions were $35.2 million, $33.5 million and $32.8 million for the years ended 2020, 2019 and 2018, respectively.

The European and Pacific Rim businesses of WAVE were included in the Sale to Knauf on September 30, 2019. Accordingly, WAVE’s European and Pacific Rim historical financial statement results have been reflected in WAVE’s consolidated financial statements as a discontinued operation for all periods presented. Our equity earnings in joint venture reflected as a component of earnings from continuing operations included $3.0 million and $1.5 million of equity earnings representing WAVE’s net earnings from operations of its discontinued European and Pacific Rim businesses in 2019 and 2018, respectively. Condensed financial data for WAVE is summarized below on a continuing operations basis.

	December 31, 2020		December 31, 2019
Current assets	$	66.8	$	99.2
Non-current assets		40.8		37.0
Current liabilities		73.0		24.4
Other non-current liabilities		234.7		287.4

	2020		2019		2018
Net sales	$	343.3	$	393.2	$	375.0
Gross profit		194.7		219.6		205.8
Net earnings		137.8		166.0		156.6

In connection with the sale of WAVE’s European and Pacific Rim businesses and operations to Knauf on September 30, 2019, WAVE recorded a $46.2 million gain on sale during 2019, which included $10.2 million of unfavorable AOCI adjustments. As such, during 2019, we recorded our share of WAVE’s gain on sale of discontinued operations of $20.6 million, which was included as a component of Equity earnings from joint venture in our Consolidated Statements of Operations and Comprehensive Income.

Our recorded investment in WAVE was higher than our 50% share of the carrying values reported in WAVE’s consolidated financial statements by $141.1 million as of December 31, 2020 and $145.8 million as of December 31, 2019. These differences are due to our adoption of fresh-start reporting upon emergence from Chapter 11 in October 2006, while WAVE’s consolidated financial statements do not reflect fresh-start reporting. The differences are composed of the following fair value adjustments to assets:

	December 31, 2020		December 31, 2019
Property, plant and equipment	$	0.4	$	0.4
Other intangibles		110.3		115.0
Goodwill		30.4		30.4
Total	$	141.1	$	145.8

Other intangibles include customer relationships, trademarks and developed technology. Customer relationships are amortized over 20 years and developed technology is amortized over 15 years. Trademarks have an indefinite life. During the third quarter of 2019, we wrote off $4.4 million of customer relationships and developed technology intangible assets attributed to WAVE’s European and Pacific Rim businesses included in the Sale. This write-off was included as a reduction to Equity earnings from joint venture in our Consolidated Statements of Operations and Comprehensive Income.

Management regularly evaluates its investment in WAVE for impairment, including performing an evaluation as a result of the sale of WAVE’s European and Pacific Rim businesses to Knauf. Based on those evaluations, management concluded that its investment in WAVE was not impaired.

See discussion in Note 26 to the Consolidated Financial Statements for additional information on this related party.