Debt and Credit Agreements - Changes in the Carrying Amount of Debt Obligations (Details) - USD ($) $ in Thousands		12 Months Ended
	Nov. 15, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Long-term Debt [Roll Forward]
Balance		$ 140,000
Proceeds		0
Repayments		(90,000)	$ (77,000)	$ (102,500)
Balance		50,000	140,000
Prior Term Loan Facility | Line of Credit
Long-term Debt [Roll Forward]
Balance		140,000
Proceeds		0
Repayments		(60,000)
Balance transfer	$ (80,000)	(80,000)
Balance		0	140,000
Current Revolving Credit Facility | Line of Credit
Long-term Debt [Roll Forward]
Balance		0
Proceeds		0
Repayments		(30,000)
Balance transfer	$ 80,000	80,000
Balance		$ 50,000	$ 0