Restricted Cash (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 181,833	$ 123,524	$ 104,147	$ 89,879
Restricted cash included in other current assets	62	353	0	0
Restricted cash included in other assets	0	19,678	20,278	21,171
Cash cash equivalents restricted cash and restricted cash equivalents	$ 181,895	143,555	$ 124,425	$ 111,050
Loss Contingency, Settlement Agreement, Terms	Prior to December 2020, the Company had restricted cash recorded in other assets related to proceeds from an inactive subsidiary of the Company which previously executed separate settlement and release agreements with two of its insurance carriers for an original total value of $35.0 million.
Proceeds Of Settlement And Release Agreements	$ 18,100
Payments Of Settlement and Release Agreements	1,000	800
Interest Income Other	$ 100	$ 200