Goodwill and Other Intangibles Investment in West Atlantic (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Interest in Joint Venture	$ 13,300	$ 12,300	$ 11,400
Equity Method Investments	10,700	10,900
Goodwill	$ 395,974	$ 395,974	$ 390,745