Deconsolidations, Discontinued Operations and Liquidation Mendota and ARS (loss) income from discontinued operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue	$ 79,424	$ 143,177
Net Investment Income	(2,957)	7,087
Net realized (losses) gains	(17)	306
Other than Temporary Impairment Losses, Investments	100	100
Gain on change in fair value of equity investments	381	0
Disposal Group, Including Discontinued Operation, Other Income	7,486	9,938
Loss and loss adjustment expenses	1,631	404
Disposal Group, Including Discontinued Operation, Other Expense	7,172	20,682
Disposal Group, Including Discontinued Operation, General and Administrative Expense	12,482	19,231
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	0	250
Disposal Group, Including Discontinued Operation, Operating Expense	78,360	160,550
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	1,064	(17,373)
Discontinued Operation, Tax Effect of Discontinued Operation	0	(1,067)
Income (loss) from discontinued operations, net of taxes	1,064	(16,306)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	(7,136)	1,017
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation	0	0
(Loss) gain on disposal of discontinued operations, net of taxes	(7,136)	1,017
Operating Income (Loss) [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue	71,182	130,443
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Investment Income	733	(353)
Net realized (losses) gains	(5)	3,465
Other than Temporary Impairment Losses, Investments	0	(316)
Gain on change in fair value of equity investments	28	0
Loss and loss adjustment expenses	58,706	120,387
(Loss) gain on disposal of discontinued operations, net of taxes	1,335
Discontinued Operations, Held-for-sale or Disposed of by Sale [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	$ (6,072)	$ (15,289)