Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Line Items]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ 17,200,000
State and local taxes, net of U.S. Federal tax	$ 7,477,000	$ (331,000)	2,238,000
Deferred state income tax asset	64,381,000	61,826,000
Deferred tax assets with respect to U.S. Federal income tax loss carryforwards	58,424,000	64,310,000
Deferred tax assets with respect to non U.S. income tax loss carryforwards	23,850,000	19,937,000
Valuation Allowance, Amount	66,298,000	62,816,000
Deferred income tax liabilities related to undistributed earnings of investments in non-U.S. subsidiaries	1,962,000	2,084,000
Income taxes receivable	6,848,000	9,313,000
Accounts payable, vehicle floor plan payable and accrued liabilities	694,521,000	574,287,000
Interest accrued related to unrecognized tax benefits	400,000
Penalties accrued related to unrecognized tax benefits	0
State [Member]
Income Taxes [Line Items]
Income tax loss carryforwards to expire	1,106,900,000
Deferred state income tax asset	64,400,000
Valuation allowance related to operating loss carryforwards	45,800,000
Non-U.S.deferred tax asset related to capital loss carryforwards	0	36,000
Valuation Allowance, Amount	49,600,000
Unrecognized tax benefit that would impact the effective tax rate	2,000,000
State [Member] | Leaf Group [Member]
Income Taxes [Line Items]
Income tax loss carryforwards to expire			115,400,000
U.S. Federal [Member]
Income Taxes [Line Items]
Income tax loss carryforwards obtained as a result of prior stock acqusitions	278,200,000
Deferred tax assets with respect to U.S. Federal income tax loss carryforwards	58,400,000
Foreign tax credit carryforwards	1,100,000
Deferred tax assets with respect to U.S. Federal foreign tax credit carryforwards	1,100,000	1,271,000
Tax Credit Carryforward, Valuation Allowance	1,100,000
Unrecognized tax benefit that would impact the effective tax rate	1,300,000
Federal tax impact of unrecognized tax benefits that would impact the effective tax rate	400,000
U.S. Federal [Member] | Leaf Group [Member]
Income Taxes [Line Items]
Income tax loss carryforwards obtained as a result of prior stock acqusitions			$ 262,500,000
non-U.S. [Member]
Income Taxes [Line Items]
Tax loss carryforwards as a result of operating losses and prior stock acquisitions	112,700,000
Deferred tax assets with respect to non U.S. income tax loss carryforwards	23,900,000
Valuation allowance against the deferred tax assets recorded for the tax losses carryforward	12,300,000
Tax loss carryforwards from operating losses and prior stock acquisitions that can be carried forward indefinitely	63,400,000
Non-U.S.deferred tax asset related to capital loss carryforwards	3,069,000	$ 3,458,000
Valuation Allowance, Amount	15,500,000
non-U.S. [Member] | Through 2028 [Member]
Income Taxes [Line Items]
Tax loss carryforwards subject to expiration	45,100,000
non-U.S. [Member] | After 2028 [Member]
Income Taxes [Line Items]
Tax loss carryforwards subject to expiration	4,200,000
Capital loss carryforward [Member] | non-U.S. [Member]
Income Taxes [Line Items]
Carryforward amount	10,200,000
Non-U.S.deferred tax asset related to capital loss carryforwards	3,100,000
Valuation Allowance, Amount	$ 3,100,000