Acquisition and Discontinued Operations Discontinued Operations - ARS (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Jun. 30, 2015	Sep. 30, 2018	Sep. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration		$ 1,700
(Loss) gain on disposal of discontinued operations, net of taxes	$ (1,172)		$ 0			$ (7,800)	$ 1,017
Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
SEC Schedule, 12-17, Insurance Companies, Reinsurance, Premium, Percentage Assumed to Net					1.25%
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) gain on disposal of discontinued operations, net of taxes		$ 1,335		$ 1,017