Summary of Significant Accounting Policies (Summary of Activity Recorded within the Allowance for Doubtful Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 5,951	$ 6,170	$ 5,599
Bad debt expense, net of recoveries	1,321	2,577	1,308
Accounts written off against allowance and other adjustments	(4,128)	(2,796)	(737)
Ending balance	3,529	5,951	$ 6,170
Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 385
Ending balance		$ 385