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Related Party Transaction (Details) - USD ($)					1 Months Ended	12 Months Ended
Related Party Transaction (Details) - USD ($)	Oct. 14, 2021	Jun. 01, 2021	Apr. 01, 2021	Jul. 01, 2020	Oct. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Long-term debt outstanding amount						$ 2,905,088,000	$ 3,132,090,000
Repurchase of non-controlling interest			$ 11,200,000			11,191,000	0
Contribution from non-controlling interest		$ 12,500,000				12,457,000	0
Decrease in custodial cash held	$ 960,000,000				$ 960,000,000
Assets under management totaled amount						956,500,000
Investment management fees						100,000
Sale of stock, consideration received on transaction				$ 90,000,000
Sale of stock, percentage of ownership				4.70%
Asset Acquisition Period One
Related Party Transaction [Line Items]
Additional deferred cash payment						25,000,000
Asset Acquisition Period Two
Related Party Transaction [Line Items]
Additional deferred cash payment						$ 25,000,000
Wellington Management Company LLP
Related Party Transaction [Line Items]
Related party, ownership interest						9.00%
Health Savings Account Assets of Bell Bank’s Healthcare Bank Division
Related Party Transaction [Line Items]
Due to related parties						$ 12,500,000
Health Savings Account Assets of Bell Bank’s Healthcare Bank Division
Related Party Transaction [Line Items]
Payments to acquire productive assets			$ 200,000,000
Common Stock Issued \| Private Placement
Related Party Transaction [Line Items]
Sale of stock, number of shares Issued in transaction (in shares)				577,254
Sale of stock, consideration received on transaction				$ 90,000,000
Secured debt
Related Party Transaction [Line Items]
Long-term debt outstanding amount						100,861,000	85,945,000
Secured debt \| Revolving line-of-credit facility under Amended and Restated Credit Agreement
Related Party Transaction [Line Items]
Long-term debt outstanding amount						119,800,000	0
Convertible Debt
Related Party Transaction [Line Items]
Long-term debt outstanding amount							310,000,000
Tranche A term loan \| Secured debt \| Revolving line-of-credit facility under Amended and Restated Credit Agreement
Related Party Transaction [Line Items]
Line of credit facility, remaining borrowing capacity						50,000,000	50,000,000
Lines of credit outstanding							0
Convertible Senior Notes Due 2027 \| Convertible Debt
Related Party Transaction [Line Items]
Long-term debt outstanding amount						$ 310,000,000	$ 310,000,000
Aggregate amount				$ 310,000,000
U.S. Health
Related Party Transaction [Line Items]
Ownership percentage by noncontrolling interest			4.53%			4.53%
Healthcare Bank
Related Party Transaction [Line Items]
Ownership percentage by noncontrolling interest		4.53%	4.53%				4.90%