Investments - Gross Unrealized Losses - Tabular Disclosure (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Gross Unrealized Losses, Less than twelve months	$ (4)	$ (639)
Fair Value, Less than twelve months	5,744	123,520
Gross Unrealized Losses, Twelve months or more	(8)	(896)
Fair Value, Twelve months or more	1,733	81,227
U.S. Government Agencies [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Gross Unrealized Losses, Less than twelve months		(32)
Fair Value, Less than twelve months		3,240
Gross Unrealized Losses, Twelve months or more		(72)
Fair Value, Twelve months or more		2,689
Mortgage-backed Securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Gross Unrealized Losses, Less than twelve months	(3)	(494)
Fair Value, Less than twelve months	4,692	100,518
Gross Unrealized Losses, Twelve months or more	(8)	(824)
Fair Value, Twelve months or more	1,733	78,538
States and Political Subdivisions [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Gross Unrealized Losses, Less than twelve months	(1)	(113)
Fair Value, Less than twelve months	$ 1,052	$ 19,762