Debt (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	May 06, 2020
Line of Credit Facility [Line Items]
Line of credit facility, outstanding	$ 0
Letters of credit outstanding, amount	13,551,000
Remaining borrowing capacity	211,449,000
Line of credit facility additional maximum borrowing capacity	$ 75,000,000
All-in interest rate	3.88%
Leverage ratio	3.00
Coverage ratio	3.00
Credit Facility, Fourth Amendment, Term Loan Tranche
Line of Credit Facility [Line Items]
Line of credit available	$ 40,000,000	$ 25,000,000
Credit Facility, Second Amendment, Term Loan Tranche | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Base rate for variable rate	1.00%
Credit Facility, Second Amendment, Term Loan Tranche | Minimum
Line of Credit Facility [Line Items]
Unused capacity, commitment fee percentage	0.35%
Credit Facility, Second Amendment, Term Loan Tranche | Minimum | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.25%
Credit Facility, Second Amendment, Term Loan Tranche | Minimum | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.25%
Credit Facility, Second Amendment, Term Loan Tranche | Maximum
Line of Credit Facility [Line Items]
Unused capacity, commitment fee percentage	0.50%
Credit Facility, Second Amendment, Term Loan Tranche | Maximum | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate	3.00%
Credit Facility, Second Amendment, Term Loan Tranche | Maximum | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.00%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt amount	$ 225,000,000	$ 200,000,000
Letter of Credit | Minimum
Line of Credit Facility [Line Items]
Unused capacity, commitment fee percentage	2.25%
Letter of Credit | Maximum
Line of Credit Facility [Line Items]
Unused capacity, commitment fee percentage	3.00%