Debt, Debt Facilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019		Dec. 31, 2018	Apr. 18, 2018
Debt [Abstract]
Current portion of long-term debt	$ 45,000		$ 69,455
April 2018 Credit Agreement [Member]
Debt [Abstract]
Unamortized debt issuance costs	3,800
April 2018 Credit Agreement Term Loan Facility [Member]
Debt [Abstract]
Original principal amount	400,000			$ 400,000
Balance	$ 380,000	[1],[2]	385,000
Interest rate	Variable 30 day: 4.75%
Interest rate	4.75%
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	$ 20,000
April 2018 Credit Agreement Revolving Credit Facility [Member]
Debt [Abstract]
Balance	$ 25,000	[1],[2]	$ 49,500
Interest rate	Variable 30 day: 4.82%
Interest rate	4.82%
Term of variable rate	30 days
Repayment terms	Revolving line of credit expires April 18, 2023.
Term of loan	5 years
Current portion of long-term debt	$ 25,000

[1] As of March 31, 2019, the current portion of the Company's debt (i.e. becoming due in the next 12 months) included $20.0 million of the balance of its term loan under the Existing Credit Agreement facility. The Company has classified the $25.0 million borrowed under the revolving line of credit as short-term debt because it is the Company's intention to use the line of credit to borrow and pay back funds over short periods of time.

[2] The carrying value of the debt reflects the amounts stated in the above table less debt issuance costs of $3.8 million as of March 31, 2019 related to the credit agreement.