SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments other than subsidiaries [Abstract]
Fixed income securities												$ 795,538	$ 592,645
Limited partnerships												23,292	55,044
Total Investments												908,424	721,783
Cash and cash equivalents	$ 67,851			$ 163,996	$ 163,996				$ 67,851	$ 163,996		67,851	163,996
OtherAssets												24,566	24,760
Total Assets												1,634,360	1,490,131
Liabilities [Abstract]
Short-term borrowings												20,000	20,000
Total Liabilities												1,270,044	1,134,049
Shareholders' equity [Abstract]
Additional paid-in capital												53,349	54,720
Accumulated other comprehensive income (loss)												9,369	(7,347)
Retained earnings												300,988	308,075
Total Shareholders' Equity												364,316	356,082	$ 418,811	$ 404,345
Total Liabilities and Shareholders' Equity												1,634,360	1,490,131
Revenue [Abstract]
Net investment income	6,815	$ 6,703	$ 6,500	6,231	6,038	$ 5,578	$ 5,796	$ 4,636	26,249	22,048	$ 18,095
Net realized gains (losses) on investments	3,848	125	2,889	6,027	(20,096)	2,373	(3,435)	(4,533)	12,889	(25,691)	19,686
Total revenues									495,597	439,169	371,234
Expenses [Abstract]
Other									138,456	137,177	113,594
Total expenses									486,924	483,041	361,112
Federal income tax benefit									1,326	(9,797)	(8,201)
Net income (loss)	3,771	(707)	1,535	2,748	(24,567)	(12,325)	2,487	330	7,347	(34,075)	18,323
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)	3,771	$ (707)	$ 1,535	2,748	(24,567)	$ (12,325)	$ 2,487	330	7,347	(34,075)	18,323
Other comprehensive income (loss), net of tax [Abstract]
Foreign currency translation adjustments									645	(830)	522
Other comprehensive income (loss)									16,716	(7,698)	13,171
Unrealized net gains (losses) on fixed income securities									16,071	(6,868)	12,649
Comprehensive income (loss)									24,063	(41,773)	31,494
Condensed Statements of Cash Flows [Abstract]
Net cash provided by operating activities									86,680	100,708	97,744
Investing activities [Abstract]
Net sales of short-term investments									0	0	500
Distributions from limited partnerships									33,396	6,869	19,230
Net purchases of property and equipment									(1,953)	(5,439)	(6,661)
Net cash provided by (used in) investing activities									(151,890)	23,651	(74,347)
Financing activities [Abstract]
Dividends paid to shareholders									(5,857)	(16,835)	(16,302)
Repurchase of common shares									(11,501)	(4,596)	(1,880)
Net cash used in financing activities									(17,358)	(21,431)	(18,182)
Increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents									(81,923)	102,098	5,737
Cash, cash equivalents and restricted cash and cash equivalents at beginning of year				163,996					163,996
Cash, cash equivalents and restricted cash and cash equivalents at end of year	67,851				163,996				67,851	163,996
Class A [Member]
Shareholders' equity [Abstract]
Common stock												111	112
Class B [Member]
Shareholders' equity [Abstract]
Common stock												499	522
Baldwin & Lyons, Inc. [Member]
Assets [Abstract]
Investment in subsidiaries												398,725	401,260
Due from affiliates												1,579	1,152
Investments other than subsidiaries [Abstract]
Fixed income securities												23,979	22,302
Limited partnerships												206	215
Total Investments												24,185	22,517
Cash and cash equivalents	7,059			15,185	15,185			26,496	7,059	26,496	14,995	7,059	15,185	$ 26,496	$ 14,995
Accounts receivable												5,606	2,276
OtherAssets												22,153	28,794
Total Assets												459,307	471,184
Liabilities [Abstract]
Premiums payable												20,238	22,964
Deposits from insureds												42,067	58,748
Short-term borrowings												20,000	20,000
Other liabilities												12,686	13,390
Total Liabilities												94,991	115,102
Shareholders' equity [Abstract]
Additional paid-in capital												53,349	54,720
Accumulated other comprehensive income (loss)												9,369	(7,347)
Retained earnings												300,988	308,075
Total Shareholders' Equity												364,316	356,082
Total Liabilities and Shareholders' Equity												459,307	471,184
Revenue [Abstract]
Commissions and service fees									14,149	17,456	18,863
Cash dividends from subsidiaries									0	5,000	10,000
Net investment income									692	569	348
Net realized gains (losses) on investments									(46)	(192)	308
Other									17	51	(106)
Total revenues									14,812	22,884	29,413
Expenses [Abstract]
Salary and related items									11,804	20,158	18,140
Other									10,386	11,724	9,686
Total expenses									22,190	31,882	27,826
Income (loss) before federal income tax benefit and equity in undistributed income of subsidiaries									(7,378)	(8,998)	1,587
Federal income tax benefit									(1,452)	(2,862)	(2,971)
Income after federal income taxes and equity in undistributed income of subsidiaries									(5,926)	(6,136)	4,558
Equity in undistributed income of subsidiaries									13,273	(27,939)	13,765
Net income (loss)									7,347	(34,075)	18,323
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)									7,347	(34,075)	18,323
Other comprehensive income (loss), net of tax [Abstract]
Foreign currency translation adjustments									645	(830)	522
Other comprehensive income (loss)									16,716	(7,698)	13,171
Unrealized net gains (losses) on fixed income securities									16,071	(6,868)	12,649
Comprehensive income (loss)									24,063	(41,773)	31,494
Condensed Statements of Cash Flows [Abstract]
Net cash provided by operating activities									10,643	14,019	44,998
Investing activities [Abstract]
Purchases of investments									(4,967)	(11,435)	(21,365)
Sales or maturities of investments									3,935	11,213	9,146
Net sales of short-term investments									0	0	0
Distributions from limited partnerships									1	0	298
Net purchases of property and equipment									(380)	(3,677)	(3,394)
Net cash provided by (used in) investing activities									(1,411)	(3,899)	(15,315)
Financing activities [Abstract]
Dividends paid to shareholders									(5,857)	(16,835)	(16,302)
Repurchase of common shares									(11,501)	(4,596)	(1,880)
Net cash used in financing activities									(17,358)	(21,431)	(18,182)
Increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents									(8,126)	(11,311)	11,501
Cash, cash equivalents and restricted cash and cash equivalents at beginning of year				$ 15,185				$ 26,496	15,185	26,496	14,995
Cash, cash equivalents and restricted cash and cash equivalents at end of year	$ 7,059				$ 15,185				$ 7,059	$ 15,185	$ 26,496
Baldwin & Lyons, Inc. [Member] | Class A [Member]
Shareholders' equity [Abstract]
Common stock												111	112
Baldwin & Lyons, Inc. [Member] | Class B [Member]
Shareholders' equity [Abstract]
Common stock												$ 499	$ 522