Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020
Debt Instrument [Line Items]
Maturity date		Jun. 19, 2023
Total long-term debt		$ 190,000		$ 261,000
Less: Debt issuance costs		(1,364)		(1,567)
Long-term debt, net		188,636		259,433
Credit Facility [Member]
Debt Instrument [Line Items]
Total long-term debt		$ 55,000		111,000
Series A [Member] | 2011 Seniors Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, interest rate	[1]	4.01%
Maturity date	[1]	Sep. 30, 2021
Total long-term debt		$ 0		75,000	[1]
Series A [Member] | 2021 Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, interest rate	[2]	4.09%
Maturity date	[2]	Jan. 12, 2026
Total long-term debt		$ 45,000	[2]	0
Series B [Member] | 2011 Seniors Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, interest rate	[1]	4.11%
Maturity date	[1]	Sep. 30, 2023
Total long-term debt	[1]	$ 75,000		75,000
Series B [Member] | 2021 Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, interest rate	[2]	4.38%
Maturity date	[2]	Jan. 12, 2028
Total long-term debt		$ 15,000	[2]	$ 0

[1] (1) Interest is payable semi-annually on March 30 and September 30.

[2] (2) Interest is payable semi-annually on June 30 and December 30.