Reserves for Unpaid Losses and Loss Adjustment Expenses Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Claims Development [Line Items]
Adverse (favorable) development on prior year loss reserves	$ (6,396)	$ (1,284)
Accident Year 2015-2018 [Member]
Claims Development [Line Items]
Adverse (favorable) development on prior year loss reserves	$ (6,300)
Accident Year 2017 [Member]
Claims Development [Line Items]
Adverse (favorable) development on prior year loss reserves		(2,500)
Accident Year 2016 [Member]
Claims Development [Line Items]
Adverse (favorable) development on prior year loss reserves		(1,200)
Accident Years 2011 to 2015 [Member]
Claims Development [Line Items]
Adverse (favorable) development on prior year loss reserves		$ 2,400