RESERVE FOR LOSSES AND LOSS EXPENSES - Incurred claims and allocated claim adjustment expenses, net of reinsurance (Details) $ in Thousands	Dec. 31, 2021 USD ($) claim	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Insurance | Property and other
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 4,695,381
Insurance | Property and other | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	335,903	$ 342,406	$ 342,723	$ 352,761	$ 353,602	$ 359,326	$ 363,521	$ 383,920	$ 402,013	$ 392,832
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 8
Cumulative number of reported claims | claim	29,793
Insurance | Property and other | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 276,632	275,403	275,919	279,588	269,153	269,504	273,448	300,371	310,545
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 1,069
Cumulative number of reported claims | claim	53,020
Insurance | Property and other | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 319,317	322,723	327,406	329,003	330,094	346,144	356,814	362,013
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 2,739
Cumulative number of reported claims | claim	62,221
Insurance | Property and other | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 245,590	256,252	254,221	257,068	261,501	272,498	279,805
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 988
Cumulative number of reported claims | claim	48,317
Insurance | Property and other | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 355,523	352,464	358,721	371,911	380,615	353,241
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 3,631
Cumulative number of reported claims | claim	93,582
Insurance | Property and other | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 807,759	811,219	822,660	830,525	905,430
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 3,783
Cumulative number of reported claims | claim	698,013
Insurance | Property and other | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 754,009	764,189	784,554	725,996
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 17,643
Cumulative number of reported claims | claim	740,146
Insurance | Property and other | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 437,227	446,574	451,522
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 17,971
Cumulative number of reported claims | claim	674,310
Insurance | Property and other | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 711,366	741,881
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 97,496
Cumulative number of reported claims | claim	699,571
Insurance | Property and other | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 452,055
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 121,860
Cumulative number of reported claims | claim	293,463
Insurance | Marine
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 1,239,840
Insurance | Marine | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	64,686	65,122	62,100	72,698	74,541	72,020	71,000	68,936	83,026	89,643
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 2,932
Cumulative number of reported claims | claim	4,135
Insurance | Marine | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 80,797	79,950	80,781	81,822	82,261	97,010	95,940	100,613	79,514
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 1,218
Cumulative number of reported claims | claim	2,356
Insurance | Marine | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 38,112	40,617	46,932	45,634	44,152	48,205	44,469	59,719
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 2,693
Cumulative number of reported claims | claim	2,169
Insurance | Marine | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 122,084	121,677	116,686	128,687	135,999	140,502	159,499
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 1,057
Cumulative number of reported claims | claim	2,232
Insurance | Marine | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 68,897	69,814	71,066	76,441	78,726	86,403
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 2,105
Cumulative number of reported claims | claim	2,867
Insurance | Marine | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 154,218	163,222	167,118	169,508	206,441
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 12,183
Cumulative number of reported claims | claim	4,038
Insurance | Marine | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 185,628	191,806	203,260	182,358
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 27,926
Cumulative number of reported claims | claim	4,426
Insurance | Marine | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 171,244	167,184	169,706
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 29,024
Cumulative number of reported claims | claim	4,668
Insurance | Marine | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 155,167	171,330
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 55,833
Cumulative number of reported claims | claim	4,491
Insurance | Marine | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 199,007
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 130,108
Cumulative number of reported claims | claim	3,447
Insurance | Aviation
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 341,659
Insurance | Aviation | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	7,205	7,302	7,383	7,590	7,703	7,760	8,709	10,795	10,670	12,782
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 36
Cumulative number of reported claims | claim	886
Insurance | Aviation | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 16,451	16,670	16,763	15,471	15,586	15,249	15,207	16,334	15,654
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 260
Cumulative number of reported claims | claim	1,043
Insurance | Aviation | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 16,716	17,350	19,097	21,857	21,798	24,357	23,038	20,437
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 121
Cumulative number of reported claims | claim	1,374
Insurance | Aviation | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 27,517	28,001	27,522	29,579	29,845	28,512	29,786
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 179
Cumulative number of reported claims | claim	2,053
Insurance | Aviation | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 32,545	32,473	31,745	33,679	33,517	29,180
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 325
Cumulative number of reported claims | claim	1,945
Insurance | Aviation | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 69,799	68,549	66,263	61,524	55,401
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ (458)
Cumulative number of reported claims | claim	4,466
Insurance | Aviation | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 61,338	61,678	63,348	57,877
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 2,610
Cumulative number of reported claims | claim	4,214
Insurance | Aviation | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 41,123	41,658	44,106
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 2,003
Cumulative number of reported claims | claim	2,778
Insurance | Aviation | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 25,380	37,391
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 6,355
Cumulative number of reported claims | claim	1,584
Insurance | Aviation | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 43,585
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 22,283
Cumulative number of reported claims | claim	1,268
Insurance | Credit and political risk
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 362,144
Insurance | Credit and political risk | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	49	199	199	199	47	10,322	12,447	12,435	15,672	32,602
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 5
Cumulative number of reported claims | claim	4
Insurance | Credit and political risk | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 12,614	12,739	12,377	14,067	14,942	9,880	9,759	25,684	26,439
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 462
Cumulative number of reported claims | claim	2
Insurance | Credit and political risk | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 69,113	70,747	71,275	69,589	68,324	67,109	70,713	38,825
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 0
Cumulative number of reported claims | claim	6
Insurance | Credit and political risk | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 24,189	24,851	25,930	26,012	27,524	30,368	30,329
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 880
Cumulative number of reported claims | claim	2
Insurance | Credit and political risk | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 25,597	26,577	42,792	42,221	44,711	45,760
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 1,081
Cumulative number of reported claims | claim	1
Insurance | Credit and political risk | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 17,592	19,804	27,634	33,148	48,555
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 8,590
Cumulative number of reported claims | claim	3
Insurance | Credit and political risk | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 27,656	35,546	36,562	43,738
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 13,354
Cumulative number of reported claims | claim	2
Insurance | Credit and political risk | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 73,471	79,778	51,407
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 16,248
Cumulative number of reported claims | claim	19
Insurance | Credit and political risk | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 69,263	60,927
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 31,314
Cumulative number of reported claims | claim	37
Insurance | Credit and political risk | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 42,600
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 39,624
Cumulative number of reported claims | claim	8
Insurance | Professional lines
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 4,051,257
Insurance | Professional lines | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	337,000	334,321	352,476	354,414	365,781	363,769	376,619	377,681	376,334	329,064
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 20,571
Cumulative number of reported claims | claim	8,348
Insurance | Professional lines | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 335,453	339,108	335,888	357,807	355,419	366,094	399,307	398,008	384,382
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 36,146
Cumulative number of reported claims | claim	9,473
Insurance | Professional lines | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 351,729	348,326	354,972	372,390	392,916	422,079	412,262	413,511
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 51,739
Cumulative number of reported claims | claim	9,858
Insurance | Professional lines | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 329,377	328,723	345,416	358,613	383,614	377,970	378,217
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 47,302
Cumulative number of reported claims | claim	10,532
Insurance | Professional lines | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 374,148	370,847	360,698	359,176	352,753	350,015
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 58,192
Cumulative number of reported claims | claim	11,909
Insurance | Professional lines | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 453,259	436,589	440,090	398,881	394,239
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 103,291
Cumulative number of reported claims | claim	13,870
Insurance | Professional lines | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 460,903	433,040	379,463	363,496
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 130,876
Cumulative number of reported claims | claim	16,765
Insurance | Professional lines | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 467,030	428,019	406,170
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 206,644
Cumulative number of reported claims | claim	16,954
Insurance | Professional lines | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 432,895	440,967
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 283,686
Cumulative number of reported claims | claim	11,622
Insurance | Professional lines | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 509,463
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 448,897
Cumulative number of reported claims | claim	8,271
Insurance | Liability
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 1,690,248
Insurance | Liability | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	61,993	64,542	67,238	72,727	75,698	68,658	71,474	74,135	71,690	70,859
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 10,249
Cumulative number of reported claims | claim	3,355
Insurance | Liability | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 94,201	89,902	91,943	95,983	93,682	88,243	95,175	95,309	93,234
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 13,218
Cumulative number of reported claims | claim	3,690
Insurance | Liability | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 132,064	132,585	131,477	132,021	130,674	129,774	124,313	107,136
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 14,321
Cumulative number of reported claims | claim	5,265
Insurance | Liability | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 187,146	188,218	182,891	165,160	137,652	127,424	128,437
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 26,055
Cumulative number of reported claims | claim	6,390
Insurance | Liability | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 120,309	120,333	127,572	128,940	130,209	124,322
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 27,993
Cumulative number of reported claims | claim	7,208
Insurance | Liability | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 206,833	202,508	185,998	165,661	167,803
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 36,274
Cumulative number of reported claims | claim	8,471
Insurance | Liability | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 205,961	192,289	169,241	168,202
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 51,462
Cumulative number of reported claims | claim	8,292
Insurance | Liability | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 222,820	193,526	192,358
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 83,628
Cumulative number of reported claims | claim	7,567
Insurance | Liability | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 225,866	225,407
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 171,715
Cumulative number of reported claims | claim	5,285
Insurance | Liability | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 233,055
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 198,167
Cumulative number of reported claims | claim	4,171
Reinsurance | Property and other
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	$ 7,234,581
Reinsurance | Property and other | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	451,567	454,280	454,701	457,952	456,536	461,542	477,396	508,032	523,613	555,785
Total of incurred-but-not-reported liabilities plus expected development on reported claims	81
Reinsurance | Property and other | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	497,825	500,490	501,123	504,433	504,945	510,944	531,304	562,186	580,230
Total of incurred-but-not-reported liabilities plus expected development on reported claims	585
Reinsurance | Property and other | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	481,788	481,582	484,443	485,213	487,065	499,636	525,809	542,903
Total of incurred-but-not-reported liabilities plus expected development on reported claims	3,587
Reinsurance | Property and other | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	453,142	456,549	451,295	455,252	460,576	465,733	478,050
Total of incurred-but-not-reported liabilities plus expected development on reported claims	1,568
Reinsurance | Property and other | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	623,977	622,706	620,858	624,507	637,746	618,765
Total of incurred-but-not-reported liabilities plus expected development on reported claims	8,053
Reinsurance | Property and other | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	1,105,803	1,110,521	1,103,419	1,080,897	1,099,195
Total of incurred-but-not-reported liabilities plus expected development on reported claims	40,302
Reinsurance | Property and other | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	1,019,138	1,014,311	1,010,076	884,369
Total of incurred-but-not-reported liabilities plus expected development on reported claims	44,435
Reinsurance | Property and other | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	924,338	949,822	951,665
Total of incurred-but-not-reported liabilities plus expected development on reported claims	78,420
Reinsurance | Property and other | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	893,869	859,634
Total of incurred-but-not-reported liabilities plus expected development on reported claims	163,285
Reinsurance | Property and other | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	783,134
Total of incurred-but-not-reported liabilities plus expected development on reported claims	425,137
Reinsurance | Professional lines
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	1,884,136
Reinsurance | Professional lines | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	205,581	203,653	207,151	214,341	212,941	222,937	224,214	221,821	216,364	209,815
Total of incurred-but-not-reported liabilities plus expected development on reported claims	8,110
Reinsurance | Professional lines | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	165,978	169,783	182,005	206,226	213,590	214,075	215,862	214,662	209,516
Total of incurred-but-not-reported liabilities plus expected development on reported claims	8,416
Reinsurance | Professional lines | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	227,369	229,236	230,376	233,896	219,509	219,552	219,610	219,544
Total of incurred-but-not-reported liabilities plus expected development on reported claims	5,971
Reinsurance | Professional lines | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	236,208	229,418	232,164	225,365	214,606	212,226	212,183
Total of incurred-but-not-reported liabilities plus expected development on reported claims	19,277
Reinsurance | Professional lines | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	256,242	256,207	228,398	200,309	196,480	195,328
Total of incurred-but-not-reported liabilities plus expected development on reported claims	32,832
Reinsurance | Professional lines | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	189,356	179,072	162,447	156,019	155,335
Total of incurred-but-not-reported liabilities plus expected development on reported claims	35,316
Reinsurance | Professional lines | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	167,128	156,429	149,373	146,729
Total of incurred-but-not-reported liabilities plus expected development on reported claims	47,916
Reinsurance | Professional lines | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	143,214	139,131	139,177
Total of incurred-but-not-reported liabilities plus expected development on reported claims	68,827
Reinsurance | Professional lines | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	143,135	141,974
Total of incurred-but-not-reported liabilities plus expected development on reported claims	105,608
Reinsurance | Professional lines | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	149,925
Total of incurred-but-not-reported liabilities plus expected development on reported claims	131,625
Reinsurance | Liability
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	2,427,680
Reinsurance | Liability | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	163,062	160,665	158,528	164,524	171,269	173,827	172,661	167,715	163,315	166,836
Total of incurred-but-not-reported liabilities plus expected development on reported claims	11,222
Reinsurance | Liability | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	154,459	156,069	157,366	177,391	184,252	184,591	182,564	175,587	171,714
Total of incurred-but-not-reported liabilities plus expected development on reported claims	12,187
Reinsurance | Liability | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	183,909	188,082	197,580	199,736	200,935	205,011	203,282	199,798
Total of incurred-but-not-reported liabilities plus expected development on reported claims	19,068
Reinsurance | Liability | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	203,913	214,132	214,011	216,257	216,437	215,460	215,061
Total of incurred-but-not-reported liabilities plus expected development on reported claims	28,578
Reinsurance | Liability | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	268,888	264,749	254,716	251,424	246,322	240,882
Total of incurred-but-not-reported liabilities plus expected development on reported claims	50,187
Reinsurance | Liability | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	299,740	290,024	280,632	271,104	275,897
Total of incurred-but-not-reported liabilities plus expected development on reported claims	73,074
Reinsurance | Liability | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	288,528	275,980	270,527	265,519
Total of incurred-but-not-reported liabilities plus expected development on reported claims	90,968
Reinsurance | Liability | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	275,176	273,309	263,805
Total of incurred-but-not-reported liabilities plus expected development on reported claims	135,114
Reinsurance | Liability | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	285,083	284,232
Total of incurred-but-not-reported liabilities plus expected development on reported claims	189,324
Reinsurance | Liability | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	304,922
Total of incurred-but-not-reported liabilities plus expected development on reported claims	265,558
Reinsurance | Credit and surety
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	1,061,038
Reinsurance | Credit and surety | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	122,058	123,383	125,625	128,662	132,213	140,246	148,622	151,401	148,841	158,822
Total of incurred-but-not-reported liabilities plus expected development on reported claims	1,642
Reinsurance | Credit and surety | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	127,065	128,319	125,497	125,376	136,675	140,863	144,733	153,538	165,106
Total of incurred-but-not-reported liabilities plus expected development on reported claims	2,445
Reinsurance | Credit and surety | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	122,149	123,430	127,133	128,434	139,862	143,576	136,403	137,007
Total of incurred-but-not-reported liabilities plus expected development on reported claims	990
Reinsurance | Credit and surety | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	140,788	139,565	138,575	157,491	161,575	166,772	160,874
Total of incurred-but-not-reported liabilities plus expected development on reported claims	3,998
Reinsurance | Credit and surety | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	114,123	116,440	124,115	149,807	141,963	142,299
Total of incurred-but-not-reported liabilities plus expected development on reported claims	2,592
Reinsurance | Credit and surety | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	116,204	118,941	127,691	133,506	139,346
Total of incurred-but-not-reported liabilities plus expected development on reported claims	6,021
Reinsurance | Credit and surety | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	112,859	115,905	121,246	112,256
Total of incurred-but-not-reported liabilities plus expected development on reported claims	13,156
Reinsurance | Credit and surety | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	69,399	69,366	75,066
Total of incurred-but-not-reported liabilities plus expected development on reported claims	10,705
Reinsurance | Credit and surety | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	84,115	77,354
Total of incurred-but-not-reported liabilities plus expected development on reported claims	40,625
Reinsurance | Credit and surety | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	52,278
Total of incurred-but-not-reported liabilities plus expected development on reported claims	36,571
Reinsurance | Motor
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	2,413,741
Reinsurance | Motor | Accident Year 2012
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	125,068	129,001	128,719	136,989	139,917	149,527	154,440	162,106	173,749	$ 182,633
Total of incurred-but-not-reported liabilities plus expected development on reported claims	9,380
Reinsurance | Motor | Accident Year 2013
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	121,852	125,709	128,823	137,925	140,724	144,202	153,715	165,656	$ 167,165
Total of incurred-but-not-reported liabilities plus expected development on reported claims	5,645
Reinsurance | Motor | Accident Year 2014
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	171,540	171,880	175,289	178,705	183,176	185,889	190,577	$ 187,744
Total of incurred-but-not-reported liabilities plus expected development on reported claims	4,531
Reinsurance | Motor | Accident Year 2015
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	216,102	219,179	220,530	232,237	230,494	226,222	$ 228,839
Total of incurred-but-not-reported liabilities plus expected development on reported claims	8,044
Reinsurance | Motor | Accident Year 2016
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	253,527	256,311	264,703	275,311	273,424	$ 252,697
Total of incurred-but-not-reported liabilities plus expected development on reported claims	7,507
Reinsurance | Motor | Accident Year 2017
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	377,449	377,101	377,357	388,304	$ 375,025
Total of incurred-but-not-reported liabilities plus expected development on reported claims	26,571
Reinsurance | Motor | Accident Year 2018
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	380,446	384,410	372,104	$ 368,844
Total of incurred-but-not-reported liabilities plus expected development on reported claims	42,305
Reinsurance | Motor | Accident Year 2019
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	349,747	348,877	$ 349,016
Total of incurred-but-not-reported liabilities plus expected development on reported claims	51,861
Reinsurance | Motor | Accident Year 2020
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	229,582	$ 225,728
Total of incurred-but-not-reported liabilities plus expected development on reported claims	71,686
Reinsurance | Motor | Accident Year 2021
Claims Development [Line Items]
Incurred claims and allocated claim adjustment expenses, net of reinsurance	188,428
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 111,017