Income Taxes - Reconciliation of Statutory Federal Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income tax expense (benefit)	$ 1,742	$ 181	$ (134)
PHL
Statutory federal tax expense (benefit)	1,349	(418)	(618)
State income tax expense (benefit), net of federal tax (benefit) expense	271	231	(110)
Other	188	335	270
Income tax expense (benefit)	$ 1,808	$ 148	$ (458)