Long-term Debt, Line of Credit and Derivatives - Provisions of Revolving Line of Credit and Accordion (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Repayments of Debt	$ 70,210,000	$ 48,111,000	$ 87,813,000
Proceeds from lines of credit	$ 63,000,000	$ 39,861,000	$ 72,000,000
Line of Credit
Debt Instrument [Line Items]
Weighted average interest rate	5.41%
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 50,000,000
Minimum additional borrowing amount	1,000,000
Amount over minimum additional borrowing amount, integral multiples	250,000
Fair value of amount outstanding	36,000,000
Remaining borrowing capacity	12,600,000
Repayments of Debt	49,000,000
Net increase in remaining borrowing capacity	14,000,000
Proceeds from lines of credit	63,000,000
Revolving Credit Facility | Line of Credit | LIBOR
Debt Instrument [Line Items]
Fair value of amount outstanding	$ 32,000,000
Weighted average interest rate	4.50%
Revolving Credit Facility | Line of Credit | Base Rate
Debt Instrument [Line Items]
Fair value of amount outstanding	$ 4,000,000
Stated interest rate	6.50%
Letter of Credit | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 20,000,000
Letters of credit outstanding	1,400,000
Swingline Loan | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	5,000,000
Minimum additional borrowing amount	250,000
Amount over minimum additional borrowing amount, integral multiples	$ 50,000