Borrowings (Loan Agreement) (Details) - USD ($)		12 Months Ended
	Jan. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 01, 2022
Line of Credit Facility [Line Items]
Loss on debt extinguishment		$ 230,000	$ 0	$ 0
Line of Credit | JPMorgan Chase Bank, N.A. | Term Loan
Line of Credit Facility [Line Items]
Maximum revolving secured credit line			80,000,000.0
Line of Credit | JPMorgan Chase Bank, N.A. | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum revolving secured credit line			$ 40,000,000.0
Loss on debt extinguishment		200,000
Line of Credit | Wells Fargo Bank
Line of Credit Facility [Line Items]
Amount outstanding		$ 13,800,000
Minimum liquidity covenant	$ 7,500,000
Line of Credit | Wells Fargo Bank | Scenario, Forecast
Line of Credit Facility [Line Items]
Minimum liquidity covenant					$ 5,000,000.0
Line of Credit | Wells Fargo Bank | Term Loan
Line of Credit Facility [Line Items]
Maximum revolving secured credit line	$ 15,000,000.0
Borrowing rate under agreement, at period end		5.15%
Amount outstanding		$ 13,600,000
Line of Credit | Wells Fargo Bank | Term Loan | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate	5.00%
Line of Credit | Wells Fargo Bank | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum revolving secured credit line	$ 55,000,000.0
Borrowing rate under agreement, at period end		1.90%
Amount outstanding		$ 200,000
Available for borrowing		$ 54,800,000
Line of Credit | Wells Fargo Bank | Revolving Credit Facility | Minimum | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.75%
Line of Credit | Wells Fargo Bank | Revolving Credit Facility | Maximum | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.25%