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Discontinued Operations - Narrative (Details) - USD ($) $ in Thousands			3 Months Ended	9 Months Ended
	Feb. 23, 2021	Jun. 30, 2020	Dec. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposal				$ 0	$ 1,881
Discontinued Operations, Disposed of by Sale \| Industrial Business Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds	$ 38,000
Net proceeds, seller note	13,000
Estimated pre-tax gain (loss)			$ (30,000)
Gain (loss) on disposal	$ (29,600)
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Apartment Tour Application Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposal		$ 1,900
Proceeds from sale of business		$ 2,000