Supplemental Guarantor Information - Condensed Consolidating Balance Sheet (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Condensed Balance Sheet Statements, Captions [Line Items]
Total cash, cash equivalents and restricted cash	$ 1,509,624,000	$ 713,337,000	$ 630,920,000	$ 549,333,000
Assets
Equity securities, trading, at fair value (cost - N/A; 2018 - N/A)	3,500,000
Debt securities	220,045,000	239,640,000
Other investments, at fair value	3,500,000	84,000
Total investments in securities	1,042,145,000	1,523,728,000
Cash and cash equivalents	693,105,000	104,183,000
Restricted cash and cash equivalents	816,519,000	609,154,000
Investment in subsidiaries	0	0
Due from brokers	0	1,411,000
Interest and dividends receivable	2,932,000	1,316,000
Reinsurance balances receivable	680,630,000	602,448,000
Deferred acquisition costs, net	166,968,000	203,842,000
Unearned premiums ceded	14,370,000	17,552,000
Loss and loss adjustment expenses recoverable	4,270,000	2,031,000	1,576,000	1,113,000
Amounts due from (to) affiliates	0	0
Other assets	17,808,000	20,569,000
Total assets	3,438,747,000	3,086,234,000
Liabilities
Accounts payable and accrued expenses	(14,607,000)	(7,261,000)
Reinsurance balances payable	98,766,000	69,701,000
Deposit liabilities	174,405,000	145,342,000		129,133,000
Unearned premium reserves	592,319,000	602,936,000
Loss and loss adjustment expense reserves	1,060,000,000	937,157,000
Participation agreement with related party investment fund	0	2,297,000
Interest and dividends payable	1,026,000	3,055,000
Senior notes payable, net of deferred costs	114,044,000	113,911,000
Total liabilities	2,055,167,000	1,881,660,000
Shareholders’ equity
Common shares	9,422,000	9,364,000
Additional paid-in capital	926,949,000	918,882,000
Retained earnings	447,209,000	276,328,000
Shareholders’ equity attributable to Third Point Re common shareholders	1,383,580,000	1,204,574,000	1,507,910,000
Total liabilities and shareholders’ equity	3,438,747,000	3,086,234,000
Eliminations
Condensed Balance Sheet Statements, Captions [Line Items]
Total cash, cash equivalents and restricted cash	0	0	0	0
Assets
Total investments in securities	0	0
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Investment in subsidiaries	(1,848,889,000)	(1,634,269,000)
Due from brokers		0
Interest and dividends receivable	0	0
Reinsurance balances receivable	0	0
Deferred acquisition costs, net	0	0
Unearned premiums ceded	0	0
Loss and loss adjustment expenses recoverable	0	0
Amounts due from (to) affiliates	0	0
Other assets	0	0
Total assets	(1,848,889,000)	(1,634,269,000)
Liabilities
Accounts payable and accrued expenses	0	0
Reinsurance balances payable	0	0
Deposit liabilities	0	0
Unearned premium reserves	0	0
Loss and loss adjustment expense reserves	0	0
Participation agreement with related party investment fund		0
Interest and dividends payable	0	0
Senior notes payable, net of deferred costs	0	0
Total liabilities	0	0
Shareholders’ equity
Common shares	(1,239,000)	(1,239,000)
Additional paid-in capital	(1,782,090,000)	(1,733,021,000)
Retained earnings	(65,560,000)	99,991,000
Shareholders’ equity attributable to Third Point Re common shareholders	(1,848,889,000)	(1,634,269,000)
Total liabilities and shareholders’ equity	(1,848,889,000)	(1,634,269,000)
Third Point Re | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Total cash, cash equivalents and restricted cash	128,000	0	0	9,000
Assets
Total investments in securities	3,500,000	0
Cash and cash equivalents	128,000	0
Restricted cash and cash equivalents	0	0
Investment in subsidiaries	1,385,519,000	1,207,161,000
Due from brokers		0
Interest and dividends receivable	0	0
Reinsurance balances receivable	0	0
Deferred acquisition costs, net	0	0
Unearned premiums ceded	0	0
Loss and loss adjustment expenses recoverable	0	0
Amounts due from (to) affiliates	(2,069,000)	(3,522,000)
Other assets	760,000	1,673,000
Total assets	1,387,838,000	1,205,312,000
Liabilities
Accounts payable and accrued expenses	(4,258,000)	(738,000)
Reinsurance balances payable	0	0
Deposit liabilities	0	0
Unearned premium reserves	0	0
Loss and loss adjustment expense reserves	0	0
Participation agreement with related party investment fund		0
Interest and dividends payable	0	0
Senior notes payable, net of deferred costs	0	0
Total liabilities	4,258,000	738,000
Shareholders’ equity
Common shares	9,422,000	9,364,000
Additional paid-in capital	926,949,000	918,882,000
Retained earnings	447,209,000	276,328,000
Shareholders’ equity attributable to Third Point Re common shareholders	1,383,580,000	1,204,574,000
Total liabilities and shareholders’ equity	1,387,838,000	1,205,312,000
TPRUSA | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Total cash, cash equivalents and restricted cash	177,000	187,000	189,000	199,000
Assets
Total investments in securities	0	0
Cash and cash equivalents	177,000	187,000
Restricted cash and cash equivalents	0	0
Investment in subsidiaries	272,433,000	251,350,000
Due from brokers		0
Interest and dividends receivable	0	0
Reinsurance balances receivable	0	0
Deferred acquisition costs, net	0	0
Unearned premiums ceded	0	0
Loss and loss adjustment expenses recoverable	0	0
Amounts due from (to) affiliates	(3,898,000)	52,000
Other assets	6,357,000	5,069,000
Total assets	275,069,000	256,658,000
Liabilities
Accounts payable and accrued expenses	(40,000)	(70,000)
Reinsurance balances payable	0	0
Deposit liabilities	0	0
Unearned premium reserves	0	0
Loss and loss adjustment expense reserves	0	0
Participation agreement with related party investment fund		0
Interest and dividends payable	1,026,000	3,055,000
Senior notes payable, net of deferred costs	114,044,000	113,911,000
Total liabilities	115,110,000	117,036,000
Shareholders’ equity
Common shares	0	0
Additional paid-in capital	191,208,000	176,005,000
Retained earnings	(31,249,000)	(36,383,000)
Shareholders’ equity attributable to Third Point Re common shareholders	159,959,000	139,622,000
Total liabilities and shareholders’ equity	275,069,000	256,658,000
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Total cash, cash equivalents and restricted cash	1,509,319,000	713,150,000	$ 630,731,000	$ 549,125,000
Assets
Total investments in securities	1,038,645,000	1,523,728,000
Cash and cash equivalents	692,800,000	103,996,000
Restricted cash and cash equivalents	816,519,000	609,154,000
Investment in subsidiaries	190,937,000	175,758,000
Due from brokers		1,411,000
Interest and dividends receivable	2,932,000	1,316,000
Reinsurance balances receivable	680,630,000	602,448,000
Deferred acquisition costs, net	166,968,000	203,842,000
Unearned premiums ceded	14,370,000	17,552,000
Loss and loss adjustment expenses recoverable	4,270,000	2,031,000
Amounts due from (to) affiliates	5,967,000	3,470,000
Other assets	10,691,000	13,827,000
Total assets	3,624,729,000	3,258,533,000
Liabilities
Accounts payable and accrued expenses	(10,309,000)	(6,453,000)
Reinsurance balances payable	98,766,000	69,701,000
Deposit liabilities	174,405,000	145,342,000
Unearned premium reserves	592,319,000	602,936,000
Loss and loss adjustment expense reserves	1,060,000,000	937,157,000
Participation agreement with related party investment fund		2,297,000
Interest and dividends payable	0	0
Senior notes payable, net of deferred costs	0	0
Total liabilities	1,935,799,000	1,763,886,000
Shareholders’ equity
Common shares	1,239,000	1,239,000
Additional paid-in capital	1,590,882,000	1,557,016,000
Retained earnings	96,809,000	(63,608,000)
Shareholders’ equity attributable to Third Point Re common shareholders	1,688,930,000	1,494,647,000
Total liabilities and shareholders’ equity	3,624,729,000	$ 3,258,533,000
Financial Guarantee | TPRUSA
Condensed Balance Sheet Statements, Captions [Line Items]
Debt obligation	$ 115,000,000.0