Long-term Debt and Line of Credit - Provisions of Revolving Line of Credit (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	May 31, 2019
Debt Instrument [Line Items]
Repayments of debt	$ 49,086,000	$ 41,225,000
Proceeds from lines of credit	33,000,000	$ 10,000,000
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	50,000,000.0		$ 50,000,000.0
Minimum borrowing increment amount	1,000,000.0
Increment borrowing multiple for amounts borrowed in excess of minimum borrowing amount	250,000
Amount outstanding	19,000,000.0
Remaining borrowing capacity	29,300,000
Repayments of debt	19,000,000.0
Increase in debt balance	14,000,000.0
Proceeds from lines of credit	33,000,000.0
Letter of Credit | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	20,000,000.0
Letters of credit outstanding	1,700,000
Bridge Loan | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	5,000,000.0
Minimum borrowing increment amount	250,000
Increment borrowing multiple for amounts borrowed in excess of minimum borrowing amount	$ 50,000