Debt, Debt Facilities (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Dec. 31, 2020	Apr. 18, 2018
Debt [Abstract]
Current portion of long-term debt		$ 90,000	$ 30,000
Credit Agreement [Member]
Debt [Abstract]
Unamortized debt issuance costs		1,900	2,100
Credit Agreement Term Loan Facility [Member]
Debt [Abstract]
Original principal amount		400,000		$ 400,000
Balance	[1],[2]	$ 330,000	337,500
Interest rate		Variable 30 day: 1.86%
Interest rate		1.86%
Term of variable rate		30 days
Repayment terms		35% of the principal amount is payable in increasing quarterly installments over a five-year period that began on June 30, 2018, with the remainder payable at the end of the five-year term.
Percentage of principal payable in installments		35.00%
Term of loan		5 years
Current portion of long-term debt		$ 30,000	30,000
Credit Agreement Revolving Credit Facility [Member]
Debt [Abstract]
Balance	[1],[2]	$ 60,000	$ 0
Interest rate		Variable 30 day: 1.86%
Interest rate		1.86%
Term of variable rate		30 days
Repayment terms		Revolving line of credit expires April 18, 2023.
Term of loan		5 years

[1] As of March 31, 2021 and December 31, 2020, the current portion of the Company’s debt (i.e. becoming due in the next 12 months) included $30.0 million of the balance of its term loan under the Credit Agreement.

[2] The carrying value of the debt reflects the amounts stated in the above table, less debt issuance costs of $1.9 million and $2.1 million as of March 31, 2021 and December 31, 2020, respectively, related to the Credit Agreement, which are not reflected in this table.