Compensation and Benefits - Restricted Share Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Weighted-Average Grant Date Fair Value
PSU outstanding subject only to qualified retirement	$ 45
Potential Class A Shares associated with 2020 PSU grant performance criteria	$ 90
Class A Common Stock
Weighted-Average Grant Date Fair Value
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period	45,000
Unvested restricted share-based awards
Weighted-Average Grant Date Fair Value
Unvested at beginning of period (in dollars per share)	$ 39.09	$ 38.18	$ 35.09
Granted (in dollars per share)	34.99	41.86	52.93
Forfeited (in dollars per share)	42.95	40.11	29.99
Vested (in dollars per share)	37.55	34.85	31.51
Unvested at end of period (in dollars per share)	$ 38.84	$ 39.09	$ 38.18	$ 35.09
Restricted Stock Awards and Restricted Stock Units
Unvested at beginning of period	5,396,343	5,245,394	5,293,642
Granted in Period, Number of Shares	517,386	788,703	741,555
Forfeited in Period, Number of Shares	(19,750)	(18,671)	(101,001)
Vested in Period, Number of Shares	(542,487)	(619,083)	(688,802)
Unvested at end of period	5,351,492	5,396,343	5,245,394	5,293,642
Performance Shares
Weighted-Average Grant Date Fair Value
Unvested at beginning of period (in dollars per share)	$ 58.13	$ 61.42	$ 52.45
Granted (in dollars per share)	0	53.50	68.58
Forfeited (in dollars per share)	0	0	0
Vested (in dollars per share)	34.97	0	0
Unvested at end of period (in dollars per share)	$ 54.89	$ 58.13	$ 61.42	$ 52.45
Restricted Stock Awards and Restricted Stock Units
Unvested at beginning of period	231,170	135,230	60,000
Granted in Period, Number of Shares	0	95,940	75,230	60,000
Forfeited in Period, Number of Shares	0	0	0
Vested in Period, Number of Shares	(15,000)	0	0
Unvested at end of period	216,170	231,170	135,230	60,000

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Potential Class A Shares associated with 2020 PSU grant performance criteria

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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-Topic 718
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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- Definition

Number of shares issued under share-based payment arrangement.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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