Long-term Debt and Line of Credit - Provisions of 364-Day Revolving Credit Facility (Details) - 364-Day Revolving Credit Facility - Line of Credit	3 Months Ended
	Mar. 31, 2021 USD ($)
Debt Instrument [Line Items]
Credit facility term	364 days
Line of credit facility, maximum borrowing capacity	$ 20,000,000.0
Minimum borrowing increment amount	1,000,000.0
Increment borrowing multiple for amounts borrowed in excess of minimum borrowing amount	250,000
Amount outstanding	$ 0