XML 66 R52.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Net Investment Gains (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2024
Realized and Unrealized Investment Gains (Losses) [Abstract] |
Realized And Unrealized Investment Gains (Losses) | Net investment gains were as follows:
(In thousands) | 2024 |  | 2023 |  | 2022
Net investment gains: |  |  |  |  |
Fixed maturity securities: |  |  |  |  |
Gains | $ | 15,486 |  |  | $ | 2,003 |  |  | $ | 4,224 |
Losses | (32,866) |  |  | (25,429) |  |  | (11,654) |
Equity securities (1): |  |  |  |  |
Net realized gains (losses) on investment sales (2) | 116,475 |  |  | 161,271 |  |  | (12,879) |
Change in unrealized gains (losses) | 120,799 |  |  | 70,448 |  |  | (632) |
Investment funds | 1,835 |  |  | (25,625) |  |  | 12,407 |
Real estate (3) (4) | (2,647) |  |  | (70,934) |  |  | 293,525 |
Loans receivable | — |  |  | (18,841) |  |  | (32) |
Other (5) | (139,344) |  |  | (45,353) |  |  | (67,648) |
Net realized and unrealized gains on investments in earnings before allowance for expected credit losses | 79,738 |  |  | 47,540 |  |  | 217,311 |
Change in allowance for expected credit losses on investments: |  |  |  |  |
Fixed maturity securities | 36,080 |  |  | 715 |  |  | (14,841) |
Loans receivable | 1,890 |  |  | (1,213) |  |  | (73) |
Change in allowance for expected credit losses on investments | 37,970 |  |  | (498) |  |  | (14,914) |
Net investment gains | 117,708 |  |  | 47,042 |  |  | 202,397 |
Income tax expense | (29,205) |  |  | (10,250) |  |  | (42,670) |
After-tax net investment gains | $ | 88,503 |  |  | $ | 36,792 |  |  | $ | 159,727 |
Change in unrealized investment gains (losses): |  |  |  |  |
Fixed maturity securities without allowance for expected credit losses | $ | 83,395 |  |  | $ | 389,839 |  |  | $ | (1,216,292) |
Fixed maturity securities with allowance for expected credit losses | 4,428 |  |  | 643 |  |  | (28,370) |
Investment funds | (3,217) |  |  | 3,989 |  |  | (2,019) |
Other | (132) |  |  | (1,568) |  |  | (1,447) |
Total change in unrealized investment gains (losses) | 84,474 |  |  | 392,903 |  |  | (1,248,128) |
Income tax (expense) benefit | (15,292) |  |  | (86,350) |  |  | 264,325 |
Noncontrolling interests | 2 |  |  | (2) |  |  | (2) |
After-tax change in unrealized investment gains (losses) | $ | 69,184 |  |  | $ | 306,551 |  |  | $ | (983,805) |
____________________ (1) The net realized gains or losses on investment sales represent the total gains or losses from the purchase dates of the equity securities. The change in unrealized gains (losses) consists of two components: (i) the reversal of the gain or loss recognized in previous periods on equity securities sold and (ii) the change in unrealized gain or loss resulting from mark-to-market adjustments on equity securities still held. (2) In 2023, the Company completed a sale of the property and casualty insurance services division of Breckenridge IS, Inc. and recognized a pre-tax net realized gain on investment of $89 million on the sale (proceeds from the sale is presented on the business disposition line within the Consolidated Statements of Cash Flows). (3) The Company recognized impairments on real estate of $72 million in 2023. (4) In 2022, the Company realized a gain on the sale of a real estate investment in London, U.K. of $251 million, net of transaction expenses and the foreign currency impact, including the reversal of the currency translation adjustment (proceeds from the real estate and related entity are presented on the business disposition line within the Consolidated Statements of Cash Flows). (5) Primarily relates to realized foreign currency losses upon the disposition of fixed maturity securities.

X
- Definition Tabular disclosure of realized and unrealized gain (loss) on investment in security. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(9)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(7)(c)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_GainLossOnInvestmentsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Realized and Unrealized Investment Gains (Losses) [Abstract] + References No definition available. + Details
Name: | wrb_RealizedAndUnrealizedInvestmentGainsLossesAbstract
Namespace Prefix: | wrb_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration