Condensed Consolidated Statements of Changes in Stockholders' Equity (unaudited) - USD ($) $ in Thousands		Total		Common stock ($0.001 par value per share)		Common stock ($0.001 par value per share) Class A Stock	Additional paid-in capital		Additional paid-in capital Class A Stock	Retained earnings		Accumulated other comprehensive income		Parent	Noncontrolling interest
Balance at beginning of period at Dec. 31, 2020	[1]			$ 13			$ 80,801			$ 601,406		$ 3,448			$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A non-voting common stock	[1]					$ 0			$ 3,996
Repurchase of Class A non-voting common stock for cancellation	[1]					0			0
Share-based expense	[1]						5,219
Vested employee share plan awards	[1]						(8,864)
Net income (loss)		$ 69,817								69,817	[1],[2]
Dividends paid	[1]									(3,030)
Currency translation adjustment		(299)										(299)	[1]
Net income (loss) attributable to noncontrolling interest		0													0	[1]
Balance at end of period at Jun. 30, 2021	[1]	752,507		13			81,152			668,193		3,149		$ 752,507	0
Balance at beginning of period at Dec. 31, 2020	[1]	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions during the year	[1]	0
Balance at end of period at Jun. 30, 2021	[1]	$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends paid per share (in dollars per share)	[1]	$ 0.24
Balance at beginning of period at Mar. 31, 2021	[1]			13			78,557			638,558		2,612			0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A non-voting common stock	[1]					0			188
Repurchase of Class A non-voting common stock for cancellation	[1]					0			0
Share-based expense	[1]						2,759
Vested employee share plan awards	[1]						(352)
Net income (loss)		$ 31,159								31,159	[1],[2]
Dividends paid	[1]									(1,524)
Currency translation adjustment		537										537	[1]
Net income (loss) attributable to noncontrolling interest		0													0	[1]
Balance at end of period at Jun. 30, 2021	[1]	752,507		13			81,152			668,193		3,149		752,507	0
Balance at beginning of period at Mar. 31, 2021	[1]	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions during the year	[1]	0
Balance at end of period at Jun. 30, 2021	[1]	$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends paid per share (in dollars per share)	[1]	$ 0.12
Balance at beginning of period at Dec. 31, 2021		$ 825,265	[3]	12	[1]		78,034	[1]		740,926	[1]	4,225	[1]		2,069	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A non-voting common stock	[1]					0			2,344
Repurchase of Class A non-voting common stock for cancellation	[1]					(1)			(46,375)
Share-based expense	[1]						6,053
Vested employee share plan awards	[1]						(4,595)
Net income (loss)		5,418								5,418	[1],[2]
Dividends paid	[1]									(3,730)
Currency translation adjustment		(2,652)										(2,652)	[1]
Net income (loss) attributable to noncontrolling interest		(360)													(360)	[1]
Balance at end of period at Jun. 30, 2022	[1]	781,368		11			35,461			742,614		1,573		779,659	1,709
Balance at beginning of period at Dec. 31, 2021	[1],[3]	127,765
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions during the year	[1]	0
Balance at end of period at Jun. 30, 2022	[1]	$ 127,765
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends paid per share (in dollars per share)	[1]	$ 0.30
Balance at beginning of period at Mar. 31, 2022	[1]			12			62,446			748,323		3,611			2,555
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A non-voting common stock	[1]					0			0
Repurchase of Class A non-voting common stock for cancellation	[1]					$ (1)			$ (30,217)
Share-based expense	[1]						3,232
Vested employee share plan awards	[1]						0
Net income (loss)		$ (3,874)								(3,874)	[1],[2]
Dividends paid	[1]									(1,835)
Currency translation adjustment		(2,038)										(2,038)	[1]
Net income (loss) attributable to noncontrolling interest		(846)													(846)	[1]
Balance at end of period at Jun. 30, 2022	[1]	781,368		$ 11			$ 35,461			$ 742,614		$ 1,573		$ 779,659	$ 1,709
Balance at beginning of period at Mar. 31, 2022	[1]	127,765
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions during the year	[1]	0
Balance at end of period at Jun. 30, 2022	[1]	$ 127,765
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends paid per share (in dollars per share)	[1]	$ 0.15

[1] Certain prior period amounts were reclassified to conform to the current period presentation, see Note 2.

[2] Attributable to Oppenheimer Holdings, Inc.

[3] Certain prior period reported amounts were reclassified to conform to the current period presentation, see Note 2