New Business (Narrative) (Details) $ / shares in Units, $ in Thousands				6 Months Ended
		Mar. 22, 2019 USD ($) $ / shares shares	May 16, 2018 USD ($)	Jun. 30, 2019 USD ($) $ / shares entity shares	Dec. 31, 2018 USD ($) $ / shares shares
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Common Stock, par value				$ 0.01	$ 0.01
Common Stock, shares issued | shares				1,217,624	1,204,196
Common Stock, shares outstanding | shares				1,217,624	1,204,196
Number of entities used for investment in private offering | entity				2
Investments Measured At NAV [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Net asset value | $	[1]			$ 2,275	$ 4,050
U.S. Insurance JV [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Required investment percentage of total equity			4.50%
U.S. Insurance JV [Member] | Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Net asset value | $			$ 3,000
U.S. Insurance JV [Member] | Investor [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Net asset value | $			$ 63,000
SPAC Fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Net asset value | $				$ 630
Insurance SPAC [Member] | IPO [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Sale of Stock, Number of Shares Issued in Transaction | shares		15,065,000
Common Stock, par value		$ 0.0001
Sale of Stock, Price Per Share		$ 10.00
Sale of Stock, Consideration Received on Transaction | $		$ 150,650
Option period		45 days
Sale of Stock, Number Of Shares For Additional Purchase | shares		1,965,000
Common Stock, shares issued | shares		20,653,333
Common Stock, shares outstanding | shares		20,653,333
Insurance SPAC [Member] | IPO [Member] | SPAC Warrant [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 11.50
Sponsor Entities [Member] | Insurance SPAC [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Period Of Required Business Combination To Occur Following IPO For Proceeds To Not Expire				18 months
Investment Owned, Balance, Shares | shares				5,103,333
Period Shares Held From Private Placement Will Not Be Transferable Or Salable				30 days
Exception Percentage Of Total Shares That Can Be Transferable Or Salable				20.00%
Period Out Of Consecutive 30 Trading Days For Transferable Or Salable Price Tranches To Hit				20 days
Sponsor Entities [Member] | Insurance SPAC [Member] | Closing Price Tranche 1 [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Sale of Stock, Price Per Share				$ 12.00
Sponsor Entities [Member] | Insurance SPAC [Member] | Closing Price Tranche 2 [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Sale of Stock, Price Per Share				13.50
Sponsor Entities [Member] | Insurance SPAC [Member] | Closing Price Tranche 3 [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Sale of Stock, Price Per Share				15.00
Sponsor Entities [Member] | Insurance SPAC [Member] | Closing Price Tranche 4 [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Sale of Stock, Price Per Share				$ 17.00
Sponsor Entities [Member] | Insurance SPAC [Member] | Private Placement [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Sale of Stock, Number of Shares Issued in Transaction | shares				375,000
Sale of Stock, Price Per Share				$ 10.00
Sale of Stock, Consideration Received on Transaction | $				$ 3,750
Period Of Private Placement Shares Not To Be Transferable, Assignable, Or Salable				30 days
Sponsor Entities [Member] | Insurance SPAC [Member] | Private Placement [Member] | Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Period Of Private Placement Share Not Exercisable				5 years
Sponsor Entities [Member] | Insurance SPAC [Member] | Investor [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Net asset value | $				$ 2,550

[1] As a practical expedient, the Company uses NAV or its equivalent to measure the fair value of its investments in EuroDekania, the U.S. Insurance JV, and the SPAC Fund. EuroDekania invests in hybrid capital securities of European companies. The U.S. Insurance JV invests in debt issued by small and medium sized U.S. and Bermuda insurance and reinsurance companies. The SPAC Fund invests in equity securities of SPACs. According to ASC 820, these investments are not categorized within the valuation hierarchy.