Allowance Accounts - Summary Of Activity In Valuation Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Uncollectible Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the beginning of period	$ 2,752	$ 1,778	$ 350
Additions		1,206	1,778
Deductions	(2,752)	(232)	(350)
Adjustments	0	0	0
Balance at the end of period	0	2,752	1,778
Deferred Tax Asset Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the beginning of period	12,337	3,771	1,936
Additions		2,788	0
Deductions	0	0	0
Adjustments	5,603	5,778	1,835
Balance at the end of period	$ 17,940	$ 12,337	$ 3,771