Short-term and Long-term Debt - 2018 Bank of America Credit Facility Narrative (Details) - USD ($)		1 Months Ended
	Jun. 28, 2021	Apr. 30, 2018	Dec. 31, 2021	Jun. 30, 2021
Short-term Debt [Line Items]
Short-term debt			$ 176,904,000	$ 63,490,000
Revolving Credit Facility | Bank of America | Line of Credit | Bank of America 2018 Credit Agreement
Short-term Debt [Line Items]
Credit facility, maximum borrowing capacity	$ 200,000,000	$ 250,000,000
Line of credit facility, accordion feature, increase limit	$ 150,000,000	$ 100,000,000
Line of credit facility, unused capacity, commitment fee percentage		0.375%
Short-term debt			$ 60,600,000	$ 0
Interest rate (as a percent)			1.50%	1.50%
Debt issuance costs			$ 500,000	$ 500,000
Credit facility, remaining borrowing capacity			$ 139,400,000
Revolving Credit Facility | Bank of America | Line of Credit | Bank of America 2018 Credit Agreement | Minimum
Short-term Debt [Line Items]
Line of credit facility, unused capacity, commitment fee percentage	0.20%
Revolving Credit Facility | Bank of America | Line of Credit | Bank of America 2018 Credit Agreement | Minimum | LIBOR
Short-term Debt [Line Items]
Credit facility, basis spread on variable rate (as a percent)	1.375%	2.00%
Revolving Credit Facility | Bank of America | Line of Credit | Bank of America 2018 Credit Agreement | Maximum
Short-term Debt [Line Items]
Line of credit facility, unused capacity, commitment fee percentage	0.30%
Revolving Credit Facility | Bank of America | Line of Credit | Bank of America 2018 Credit Agreement | Maximum | LIBOR
Short-term Debt [Line Items]
Credit facility, basis spread on variable rate (as a percent)	1.625%	3.00%