Credit Risk and Allowance for Credit Losses - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
January 1	$ 428	$ 384
Provision for expected credit losses	82	325
March 31	$ 428	$ 384	$ 510	$ 709