Subsequent events (Details) - USD ($)	Jul. 31, 2018	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Subsequent Event [Line Items]
Total investments in securities		$ 3,098,125,000	$ 2,995,939,000
Total assets		4,909,619,000	4,671,794,000
Total liabilities		3,305,530,000	2,902,079,000
Shareholders’ equity attributable to Third Point Re common shareholders		1,591,754,000	1,656,089,000	$ 1,556,323,000
Total shareholders’ equity		1,596,910,000	$ 1,661,496,000	$ 1,576,132,000
Pro Forma [Member]
Subsequent Event [Line Items]
Total investments in securities		1,991,129,000
Total assets		3,504,693,000
Total liabilities		1,912,939,000
Shareholders’ equity attributable to Third Point Re common shareholders		1,591,754,000
Total shareholders’ equity		$ 1,591,754,000
Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Amount borrowed under revolving credit facility	$ 200,000,000
Collateral Fees Percentage	1.50%
Commitment Fee Percentage	0.20%
Minimum Net Worth Covenant	$ 1,114.2
Debt [Member] | Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Debt to Equity Ratio Covenant	35.00%
Stockholders' Equity, Total [Member] | Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Debt to Equity Ratio Covenant	100.00%