Leases - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year	$ 6,480	$ 8,621
Additions Charged Against Operations	1,910	26
Uncollectible Accounts Written-off	(2,592)	(2,167)
Balance at End of Year	$ 5,798	$ 6,480