Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Valuation Allowance [Line Items]
Threshold past due account balances for reserve analysis	$ 20,000
Threshold Past Due Days For Reserve Analysis	60
SEC Schedule, 12-09, Allowance, Credit Loss
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 5,472,000	$ 6,182,000
Bad debt expense	1,996,000	1,646,000
Write-offs, net of recoveries	(1,510,000)	(1,413,000)
Balance at end of period	$ 5,958,000	$ 6,415,000