Long-term Debt, Line of Credit and Derivatives - Provisions of Revolving Line of Credit (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Debt Instrument [Line Items]
Repayments of Debt	$ 24,500,000	$ 29,500,000
Proceeds from lines of credit	$ 5,000,000	$ 32,000,000
Line of Credit
Debt Instrument [Line Items]
Weighted average interest rate	3.15%
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 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	18,000,000.0
Remaining borrowing capacity	29,900,000
Repayments of Debt	23,000,000.0
Decrease in debt balance	18,000,000.0
Proceeds from lines of credit	$ 5,000,000.0
Revolving Credit Facility | Line of Credit | LIBOR
Debt Instrument [Line Items]
Weighted average interest rate	2.69%
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	2,100,000
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