Fair Value of Financial Instruments (Level 3 Securities) (Details) - Recurring - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 1,546	$ 1,511
Net unrealized gains	43	78
Ending Balance	1,589	1,589
Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	250	250
Net unrealized gains	0	0
Ending Balance	250	250
Asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	701	666
Net unrealized gains	43	78
Ending Balance	744	744
Equities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	595	595
Net unrealized gains	0	0
Ending Balance	$ 595	$ 595