Related Party Transactions (Detail) (USD $) Share data in Millions, unless otherwise specified	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 05, 2014	Aug. 31, 2014
Effective date	August 8, 2014
Management fee percentage					75.00%
Receivable for advisory and service fees, from affiliates	$ 10,402,000	$ 6,839,000
Compensation and management fee	155,560,000	167,366,000	190,702,000
Maximum
Management fee percentage					120.00%
Amendment Agreement
Basis for management fee				Amount equal to 1/12th of 1.05% of stockholders' equity,
Management Agreement, term				2 years
Term of management agreement expiration date				Dec. 31, 2016
Renewal term				2 years
Management agreement, termination, description				At least two-thirds of the Company's independent directors or the holders of a majority of the Company's outstanding shares of common stock elect to terminate the agreement in their sole discretion and for any or no reason.
Amendment Agreement | Minimum
Management agreement, required period to terminate from the date of the notice				1 year
Chimera
Investments with affiliate, available-for-sale equity securities - shares	45.0	45.0
Investments with affiliate, available-for-sale equity securities - fair value	143,000,000	139,400,000
Investments with affiliate, available-for-sale equity securities - unrealized gains	4,200,000	600,000
Advisory fees from affiliate	31,300,000
Receivable for advisory and service fees, from affiliates	10,400,000	6,800,000
Chimera | Deferred Derivative Gain (Loss) [Member]
One-time payment made to related party	23,800,000
Chimera and CreXus
Advisory fees from affiliate		31,100,000
Management Agreement
Compensation and management fee	155,600,000	167,400,000
Management fee payable	11,000,000	16,200,000
Management Agreement | Subsidiaries
Compensation expense	$ 24,200,000	$ 49,200,000