Revenues from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 511,579	$ 469,119
United States
Disaggregation of Revenue [Line Items]
Revenues	438,121	400,200
United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	39,066	36,941
Canada
Disaggregation of Revenue [Line Items]
Revenues	11,270	11,459
Ireland
Disaggregation of Revenue [Line Items]
Revenues	16,334	15,130
Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	6,788	5,389
Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	103,510	105,002
Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	107,609	103,409
Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	175,850	147,540
Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	70,818	63,368
Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	30,663	29,091
Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	5,715	5,802
Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	17,414	14,907
Private Banks
Disaggregation of Revenue [Line Items]
Revenues	130,137	120,902
Private Banks \| United States
Disaggregation of Revenue [Line Items]
Revenues	85,775	78,469
Private Banks \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	29,848	27,846
Private Banks \| Canada
Disaggregation of Revenue [Line Items]
Revenues	9,799	10,090
Private Banks \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	4,715	4,497
Private Banks \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	0	0
Private Banks \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	32,399	32,220
Private Banks \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	931	498
Private Banks \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	539	346
Private Banks \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	67,846	60,865
Private Banks \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	23,459	22,215
Private Banks \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	4,115	3,792
Private Banks \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	848	966
Investment Advisors
Disaggregation of Revenue [Line Items]
Revenues	122,718	106,538
Investment Advisors \| United States
Disaggregation of Revenue [Line Items]
Revenues	122,718	106,538
Investment Advisors \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Advisors \| Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Advisors \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Advisors \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Advisors \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	58,597	60,605
Investment Advisors \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	48,161	40,666
Investment Advisors \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	9,644	0
Investment Advisors \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	1,281	1,254
Investment Advisors \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Advisors \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Advisors \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	5,035	4,013
Institutional Investors
Disaggregation of Revenue [Line Items]
Revenues	71,778	74,290
Institutional Investors \| United States
Disaggregation of Revenue [Line Items]
Revenues	59,376	62,218
Institutional Investors \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	9,218	9,095
Institutional Investors \| Canada
Disaggregation of Revenue [Line Items]
Revenues	1,471	1,369
Institutional Investors \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	1,713	1,608
Institutional Investors \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	0	0
Institutional Investors \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	12,074	11,713
Institutional Investors \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	54,209	58,028
Institutional Investors \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	0	0
Institutional Investors \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	423	194
Institutional Investors \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	2,088	2,651
Institutional Investors \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	0	0
Institutional Investors \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	2,984	1,704
Investment Managers
Disaggregation of Revenue [Line Items]
Revenues	172,653	154,497
Investment Managers \| United States
Disaggregation of Revenue [Line Items]
Revenues	155,959	140,083
Investment Managers \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Managers \| Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Managers \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	9,906	9,025
Investment Managers \| Luxembourg
Disaggregation of Revenue [Line Items]
Revenues	6,788	5,389
Investment Managers \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	84	126
Investment Managers \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investment Managers \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	164,189	145,639
Investment Managers \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	1,258	1,044
Investment Managers \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	19	18
Investment Managers \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	1,017	1,661
Investment Managers \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	6,086	6,009
Investments In New Businesses
Disaggregation of Revenue [Line Items]
Revenues	14,293	12,892
Investments In New Businesses \| United States
Disaggregation of Revenue [Line Items]
Revenues	14,293	12,892
Investments In New Businesses \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investments In New Businesses \| Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investments In New Businesses \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	0	0
Investments In New Businesses \| Luxembourg
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	356	338
Investments In New Businesses \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	4,308	4,217
Investments In New Businesses \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	1,478	1,555
Investments In New Businesses \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	10	11
Investments In New Businesses \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	5,097	4,207
Investments In New Businesses \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	583	349
Investments In New Businesses \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	$ 2,461	$ 2,215