Debt (Narrative) (Details)						3 Months Ended			9 Months Ended
		Sep. 30, 2023 USD ($)		Sep. 26, 2023 USD ($)	Jul. 28, 2023 USD ($)	Sep. 30, 2023 USD ($)		Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)		Sep. 30, 2022 USD ($)	Sep. 30, 2023 GBP (£)	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Average borrowings outstanding						$ 737,700,000		$ 714,100,000	$ 737,100,000		$ 676,500,000
Weighted average interest rate						6.20%		4.90%	6.00%		4.60%
Interest Expense, Net						$ (9,824,000)		$ (10,776,000)	$ (33,140,000)		$ (36,755,000)
Interest expense						11,810,000		11,579,000	37,878,000		38,969,000
5.75% Unsecured Notes maturing in 2026 [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs		$ 1,900,000				$ 1,900,000			$ 1,900,000				$ 2,500,000
Interest rate		5.75%				5.75%			5.75%			5.75%	5.75%
Fair value of debt instrument		$ 387,100,000				$ 387,100,000			$ 387,100,000				$ 395,100,000
Five-Year Credit Agreement maturing in 2027 [Member]
Debt Instrument [Line Items]
Credit facility current borrowing capacity		300,000,000				300,000,000			300,000,000
Line of credit facility outstanding		60,895,000				60,895,000			60,895,000				200,236,000
GBP revolving credit facility borrowings [Member]
Debt Instrument [Line Items]
Line of credit facility outstanding | £												£ 50,000,000
Term Loan maturing in 2027 - $150 million [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs		700,000				700,000			700,000
Loans Payable to Bank		149,303,000	[1]		$ 150,000,000	149,303,000	[1]		149,303,000	[1]			0	[1]
Debt Instrument, Periodic Payment, Principal					$ 1,875,000
Real Estate Term Loan maturing in 2028 - $75.2 million [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs		100,000				100,000			100,000
Loans Payable to Bank	[2]	$ 75,165,000				$ 75,165,000			$ 75,165,000				0
Interest rate		7.07%				7.07%			7.07%			7.07%
Capital Term Loan maturing in 2028 - $65 million [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs		$ 900,000				$ 900,000			$ 900,000
Loans Payable to Bank	[3]	$ 64,137,000				$ 64,137,000			$ 64,137,000				0
Interest rate		7.32%				7.32%			7.32%			7.32%
Commercial note with Truist Bank maturing in 2031 - $24.75 million [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs													100,000
Commercial note with Truist Bank maturing in 2032 - $27.2 million [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs													$ 100,000
Secured Overnight Financing Rates (SOFR) [Member] | Term Loan maturing in 2027 - $150 million [Member]
Debt Instrument [Line Items]
Applicable interest rate margin					1.75%
Sterling Overnight Interbank Average Rate (SONIA) [Member] | GBP revolving credit facility borrowings [Member]
Debt Instrument [Line Items]
Applicable interest rate margin		1.375%
Automotive [Member] | Real Estate Term Loan maturing in 2028 - $75.2 million [Member]
Debt Instrument [Line Items]
Loans Payable to Bank				$ 75,200,000
Debt Instrument, Periodic Payment, Principal				300,000
Automotive [Member] | Capital Term Loan maturing in 2028 - $65 million [Member]
Debt Instrument [Line Items]
Loans Payable to Bank				65,000,000
Debt Instrument, Periodic Payment, Principal				500,000
Automotive [Member] | Delayed Draw Term Loan maturing in 2028 - $50 million [Member]
Debt Instrument [Line Items]
Loans Payable to Bank		$ 0				$ 0			$ 0
Term Loan, Unused Borrowing Capacity, Amount				50,000,000
Automotive [Member] | Interest Rate Swap maturing in 2028 - $75.2 million [Member]
Debt Instrument [Line Items]
Derivative, Notional Amount				$ 75,200,000
Derivative, Fixed Interest Rate				4.67%
Total fixed interest rate of debt		6.42%				6.42%			6.42%			6.42%
Automotive [Member] | Interest Rate Swaps maturing in 2031 and 2032 [Member]
Debt Instrument [Line Items]
Realized gain from termination of interest rate swap						$ 4,600,000
Automotive [Member] | Secured Overnight Financing Rates (SOFR) [Member] | Real Estate Term Loan maturing in 2028 - $75.2 million [Member]
Debt Instrument [Line Items]
Applicable interest rate margin				1.75%
Automotive [Member] | Secured Overnight Financing Rates (SOFR) [Member] | Capital Term Loan maturing in 2028 - $65 million [Member]
Debt Instrument [Line Items]
Applicable interest rate margin				2.00%
Automotive [Member] | Secured Overnight Financing Rates (SOFR) [Member] | Interest Rate Swap maturing in 2028 - $75.2 million [Member]
Debt Instrument [Line Items]
Derivative, Basis Spread on Variable Rate				1.75%
Securities Subject to Mandatory Redemption [Member] | Graham Healthcare Group [Member]
Debt Instrument [Line Items]
Interest expense						$ 1,100,000		$ 1,400,000	$ 1,400,000		$ 12,800,000

[1] The carrying value is net of $0.7 million of unamortized debt issuance costs as of September 30, 2023.

[2] The carrying value is net of $0.1 million of unamortized debt issuance costs as of September 30, 2023.

[3] The carrying value is net of $0.9 million of unamortized debt issuance costs as of September 30, 2023.