CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY AND REDEEMABLE NONCONTROLLING INTERESTS (unaudited) - USD ($)	Total	Class A Stock	Parent	Common Stock	Common Stock Class A Stock	Additional paid-in capital	Additional paid-in capital Class A Stock	Retained earnings		Retained earnings Class A Stock	Accumulated other comprehensive income	Noncontrolling interest
Balance at beginning of period at Dec. 31, 2022				$ 11,000		$ 28,628,000		$ 764,178,000			$ 1,416,000	$ 722,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A non-voting common stock					$ 0		$ 5,672,000
Repurchase of Class A non-voting common stock for cancellation		$ (7,300,000)			0		(3,687,000)			$ (3,599,000)
Share-based expense						6,642,000
Vested employee share plan awards						(11,578,000)
Capital addition to noncontrolling interest												171,000
Net income (loss)	$ 4,896,000							5,217,000	[1]			(321,000)
Change in redemption value of redeemable noncontrolling interests	565,000					(101,000)						(464,000)
Dividends paid								(3,325,000)
Currency translation adjustment	(1,160,000)										(1,160,000)
Balance at end of period at Jun. 30, 2023	788,422,000		$ 788,314,000	11,000		25,576,000		762,471,000			256,000	108,000
Balance at beginning of period at Dec. 31, 2022	25,466,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Redemption of redeemable noncontrolling interests	(83,000)
Change in redemption value of redeemable noncontrolling interests	565,000					(101,000)						(464,000)
Balance at end of period at Jun. 30, 2023	$ 25,948,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends paid per share (in dollars per share)	$ 0.30
Balance at beginning of period at Dec. 31, 2022				11,000		28,628,000		764,178,000			1,416,000	722,000
Balance at end of period at Dec. 31, 2023	$ 789,239,000			10,000		31,774,000		756,468,000			914,000	73,000
Balance at beginning of period at Dec. 31, 2022	25,466,000
Balance at end of period at Dec. 31, 2023	0
Balance at beginning of period at Mar. 31, 2023				11,000		22,374,000		777,121,000			919,000	433,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A non-voting common stock					0		184,000
Repurchase of Class A non-voting common stock for cancellation		(3,600,000)			0		0			(3,599,000)
Share-based expense						3,349,000
Vested employee share plan awards						(259,000)
Capital addition to noncontrolling interest												171,000
Net income (loss)	(9,568,000)							(9,400,000)	[1]			(168,000)
Change in redemption value of redeemable noncontrolling interests	400,000					(72,000)						(328,000)
Dividends paid								(1,651,000)
Currency translation adjustment	(663,000)										(663,000)
Balance at end of period at Jun. 30, 2023	788,422,000		788,314,000	11,000		25,576,000		762,471,000			256,000	108,000
Balance at beginning of period at Mar. 31, 2023	25,557,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Redemption of redeemable noncontrolling interests	(9,000)
Change in redemption value of redeemable noncontrolling interests	400,000					(72,000)						(328,000)
Balance at end of period at Jun. 30, 2023	$ 25,948,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends paid per share (in dollars per share)	$ 0.15
Balance at beginning of period at Dec. 31, 2023	$ 789,239,000			10,000		31,774,000		756,468,000			914,000	73,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A non-voting common stock					0		8,409,000
Repurchase of Class A non-voting common stock for cancellation		(9,300,000)			0		(8,384,000)			(924,000)
Share-based expense						6,470,000
Vested employee share plan awards						(15,168,000)
Capital addition to noncontrolling interest												237,000
Net income (loss)	36,010,000							36,320,000	[1]			(310,000)
Change in redemption value of redeemable noncontrolling interests	0					264,000						0
Dividends paid								(3,125,000)
Currency translation adjustment	(967,000)										(968,000)
Balance at end of period at Jun. 30, 2024	812,060,000		812,060,000	10,000		23,365,000		788,739,000			(54,000)	0
Balance at beginning of period at Dec. 31, 2023	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Redemption of redeemable noncontrolling interests	0
Change in redemption value of redeemable noncontrolling interests	0					264,000						0
Balance at end of period at Jun. 30, 2024	$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends paid per share (in dollars per share)	$ 0.30
Balance at beginning of period at Mar. 31, 2024				10,000		20,040,000		780,946,000			526,000	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A non-voting common stock					0		171,000
Repurchase of Class A non-voting common stock for cancellation		$ (924,364)			$ 0		$ 0			$ (924,000)
Share-based expense						3,325,000
Vested employee share plan awards						(171,000)
Capital addition to noncontrolling interest												0
Net income (loss)	$ 10,266,000							10,266,000	[1]			0
Change in redemption value of redeemable noncontrolling interests	0					0						0
Dividends paid								(1,549,000)
Currency translation adjustment	(580,000)										(580,000)
Balance at end of period at Jun. 30, 2024	812,060,000		$ 812,060,000	$ 10,000		23,365,000		$ 788,739,000			$ (54,000)	0
Balance at beginning of period at Mar. 31, 2024	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Redemption of redeemable noncontrolling interests	0
Change in redemption value of redeemable noncontrolling interests	0					$ 0						$ 0
Balance at end of period at Jun. 30, 2024	$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends paid per share (in dollars per share)	$ 0.15

[1] (1) Attributable to Oppenheimer Holdings Inc.