Restricted Cash (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 123,524	$ 104,147	$ 89,879	$ 88,818
Restricted cash included in other current assets	353	0	0	0
Restricted cash included in other assets	19,678	20,278	21,171	21,883
Cash cash equivalents restricted cash and restricted cash equivalents	$ 143,555	124,425	$ 111,050	$ 110,701
Loss Contingency, Settlement Agreement, Terms	The Company has 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. The proceeds of both settlements are restricted and can only be used to pay claims and costs of defense associated with the subsidiary’s asbestos litigation. The proceeds of the settlement and release agreements have been deposited into interest bearing accounts which earned $0.2 million in both the years ended December 31, 2019 and 2018, offset by $0.8 million and $1.1 million of net payments during 2019 and 2018, respectively
Proceeds Of Settlement And Release Agreements	$ 200	200
Payments Of Settlement and Release Agreements	$ 800	$ 1,100