Revenues from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 476,759	$ 471,334	$ 1,434,935	$ 1,534,447
United States
Disaggregation of Revenue [Line Items]
Revenues	406,184	403,526	1,225,796	1,234,242
United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	37,231	36,915	110,840	204,803
Canada
Disaggregation of Revenue [Line Items]
Revenues	11,491	11,852	34,544	37,341
Ireland
Disaggregation of Revenue [Line Items]
Revenues	15,639	14,501	46,324	46,078
Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	6,214	4,507	17,431	11,721
Other
Disaggregation of Revenue [Line Items]
Revenues		33		262
Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	104,461	107,066	315,840	342,202
Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	104,632	105,427	313,564	328,575
Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	157,055	144,517	457,643	435,342
Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	61,896	57,818	189,322	170,651
Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	28,532	36,468	87,332	109,572
Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	4,909	3,993	25,826	101,842
Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	15,274	16,045	45,408	46,263
Private Banks
Disaggregation of Revenue [Line Items]
Revenues	121,469	122,660	378,171	460,392
Private Banks \| United States
Disaggregation of Revenue [Line Items]
Revenues	78,306	81,628	249,759	244,472
Private Banks \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	28,789	27,186	84,619	171,042
Private Banks \| Canada
Disaggregation of Revenue [Line Items]
Revenues	10,060	10,495	30,297	33,318
Private Banks \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	4,314	3,351	13,496	11,560
Private Banks \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Private Banks \| Other
Disaggregation of Revenue [Line Items]
Revenues		0		0
Private Banks \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	32,119	30,002	96,432	95,113
Private Banks \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	900	633	2,210	1,504
Private Banks \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	336	336	1,019	1,040
Private Banks \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	60,564	57,818	185,320	170,651
Private Banks \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	21,972	29,855	66,913	89,259
Private Banks \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	4,539	3,195	23,213	100,020
Private Banks \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	1,039	821	3,064	2,805
Private Banks \| Professional services fees, one-time early termination fees
Disaggregation of Revenue [Line Items]
Revenues			10,457	88,000
Investment Advisors
Disaggregation of Revenue [Line Items]
Revenues	110,461	109,565	326,579	341,989
Investment Advisors \| United States
Disaggregation of Revenue [Line Items]
Revenues	110,461	109,565	326,579	341,989
Investment Advisors \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors \| Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	0		0
Investment Advisors \| Other
Disaggregation of Revenue [Line Items]
Revenues		0		0
Investment Advisors \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	60,046	63,688	181,754	203,171
Investment Advisors \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	45,175	39,915	129,000	122,321
Investment Advisors \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	2	0	0	0
Investment Advisors \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	1,183	0	3,479	0
Investment Advisors \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	4,055	5,962	12,346	16,497
Institutional Investors
Disaggregation of Revenue [Line Items]
Revenues	70,479	78,260	219,914	248,582
Institutional Investors \| United States
Disaggregation of Revenue [Line Items]
Revenues	58,992	65,571	184,332	204,836
Institutional Investors \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	8,442	9,729	26,221	33,761
Institutional Investors \| Canada
Disaggregation of Revenue [Line Items]
Revenues	1,431	1,357	4,247	4,023
Institutional Investors \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	1,614	1,570	5,114	5,700
Institutional Investors \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Institutional Investors \| Other
Disaggregation of Revenue [Line Items]
Revenues		33		262
Institutional Investors \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	11,858	12,928	36,295	42,494
Institutional Investors \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	54,317	60,887	169,875	192,559
Institutional Investors \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Institutional Investors \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	50	0	330	0
Institutional Investors \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	2,291	2,650	7,733	8,781
Institutional Investors \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Institutional Investors \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	1,963	1,795	5,681	4,748
Investment Managers
Disaggregation of Revenue [Line Items]
Revenues	169,293	156,015	495,318	468,842
Investment Managers \| United States
Disaggregation of Revenue [Line Items]
Revenues	153,368	141,928	450,173	428,303
Investment Managers \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Managers \| Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Managers \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	9,711	9,580	27,714	28,818
Investment Managers \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	6,214	4,507	17,431	11,721
Investment Managers \| Other
Disaggregation of Revenue [Line Items]
Revenues		0		0
Investment Managers \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	87	81	318	288
Investment Managers \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Managers \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	156,717	144,181	456,624	434,302
Investment Managers \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	86	0	160	0
Investment Managers \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	4,269	3,963	12,686	11,532
Investment Managers \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	370	798	2,613	1,822
Investment Managers \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	7,764	6,992	22,917	20,898
Investments In New Businesses
Disaggregation of Revenue [Line Items]
Revenues	5,057	4,834	14,953	14,642
Investments In New Businesses \| United States
Disaggregation of Revenue [Line Items]
Revenues	5,057	4,834	14,953	14,642
Investments In New Businesses \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses \| Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	0		0
Investments In New Businesses \| Other
Disaggregation of Revenue [Line Items]
Revenues		0		0
Investments In New Businesses \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	351	367	1,041	1,136
Investments In New Businesses \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	4,240	3,992	12,479	12,191
Investments In New Businesses \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	13	0	33	0
Investments In New Businesses \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	$ 453	$ 475	$ 1,400	$ 1,315