Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Cantor	Smith Mack	Common Stock Class A Common Stock	Common Stock Class A Common Stock Smith Mack	Common Stock Class B Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Cantor	Additional Paid-in Capital Smith Mack	Treasury Stock	Retained Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest in Subsidiaries	Noncontrolling Interest in Subsidiaries Cantor	Noncontrolling Interest in Subsidiaries Smith Mack
Beginning Balance at Dec. 31, 2021	$ 663,315			$ 4,359		$ 459	$ 2,451,135			$ (623,734)	$ (1,171,919)	$ (40,548)	$ 43,563
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	30,701										25,972		4,729
Other comprehensive income (loss), net of tax	3,795											3,425	370
Equity-based compensation	6,299			20			4,773						1,506
Dividends to common stockholders	(3,710)										(3,710)
Earnings distributions to limited partnership interests and other noncontrolling interests	1,577												1,577
Grant of exchangeability and redemption of limited partnership interests	30,047			67			22,533						7,447
Issuance of Class A common stock (net of costs)	152		$ 1,976	0	$ 9		148		$ 1,661				4		$ 306
Redemption of FPUs	(84)												(84)
Contributions of capital to and from Cantor for equity-based compensation		$ 1,830						$ 1,392						$ 438
Other	(234)						(234)						0
Ending Balance at Mar. 31, 2022	$ 735,664			4,455		459	2,481,408			(623,734)	(1,149,657)	(37,123)	59,856
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per share of common stock (in dollars per share)	$ 0.01
Common stock, dividends, per share, cash paid (in dollars per share)	$ 0.01
Beginning Balance at Dec. 31, 2022	$ 733,208			4,719		459	2,559,418			(711,454)	(1,138,066)	(45,431)	63,563
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	21,170										18,978		2,192
Other comprehensive income (loss), net of tax	2,268											1,909	359
Equity-based compensation	7,060			21			5,374						1,665
Dividends to common stockholders	(3,739)										(3,739)
Earnings distributions to limited partnership interests and other noncontrolling interests	(6,453)												(6,453)
Grant of exchangeability and redemption of limited partnership interests	48,549		$ 2,761	131	$ 7		36,694		$ 2,340				11,724		$ 414
Issuance of Class A common stock (net of costs)	196			0			186						10
Redemption of FPUs	(66)												(66)
Repurchase of Class A common stock	(4,208)									(3,575)			(633)
Forfeiture of Class A common stock	(49)						10			(52)			(7)
Contributions of capital to and from Cantor for equity-based compensation		$ 355						$ 271						$ 84
Other	(34)						(34)						0
Ending Balance at Mar. 31, 2023	$ 801,018			$ 4,878		$ 459	$ 2,604,259			$ (715,081)	$ (1,122,827)	$ (43,522)	$ 72,852
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per share of common stock (in dollars per share)	$ 0.01
Common stock, dividends, per share, cash paid (in dollars per share)	$ 0.01