CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
U.S. Treasury securities, pledged assets	$ 1,113,027	$ 752,076
Agency mortgage-backed securities, pledged assets	63,897,873	107,466,084
Agency debentures, pledged assets	2,931,261	981,727
Receivable for investment advisory income, from affiliates	6,839	14,077
Intangible for customer relationships, accumulated amortization	$ 0	$ 5,779
Common Stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,956,937,500	1,956,937,500
Common Stock, shares issued	947,432,862	947,213,204
Common Stock, shares outstanding	947,432,862	947,213,204
7.875% Series A Cumulative Redeemable Preferred Stock
Preferred Stock, shares authorized	7,412,500	7,412,500
Preferred Stock, shares issued	7,412,500	7,412,500
Preferred Stock, shares outstanding	7,412,500	7,412,500
7.625% Series C Cumulative Redeemable Preferred Stock
Preferred Stock, shares authorized	12,650,000	12,650,000
Preferred Stock, shares issued	12,000,000	12,000,000
Preferred Stock, shares outstanding	12,000,000	12,000,000
7.50% Series D Cumulative Redeemable Preferred Stock
Preferred Stock, shares authorized	18,400,000	18,400,000
Preferred Stock, shares issued	18,400,000	18,400,000
Preferred Stock, shares outstanding	18,400,000	18,400,000