CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 10,762	$ 19,785
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Net investment gain	(2,808)	(11,224)
Net (discount)/premium (accretion)/amortization on mortgage-backed securities	(2,633)	(4,061)
Depreciation and amortization	12	12
Other	161	391
Changes in operating assets
Interest receivable	(169)	(1,143)
Other receivables	(4)	(337)
Prepaid expenses and other assets	1,470	(8,937)
Changes in operating liabilities
Accounts payable and accrued expenses	302	(431)
Accrued compensation and benefits	(4,863)	(2,892)
Net cash provided by (used in) operating activities	2,230	(8,837)
Cash flows from investing activities:
Purchases of available-for-sale mortgage-backed securities	0	(10,978)
Purchases of trading mortgage-backed securities	(170,224)	(495,974)
Proceeds from sales of available-for-sale mortgage-backed securities	0	62,030
Proceeds from sales of trading mortgage-backed securities	21,548	105,603
Receipt of principal payments on available-for-sale mortgage-backed securities	3,516	5,733
Receipt of principal payments on trading mortgage-backed securities	13,771	6,862
Changes in purchased securities payable	61,611	(2,555)
Changes in sold securities receivable	19,712	0
Proceeds from derivatives and deposits, net	926	4,120
Other	(1,740)	(71)
Net cash used in investing activities	(50,880)	(325,230)
Cash flows from financing activities:
Proceeds from repurchase agreements, net	20,641	347,828
Proceeds from stock issuance	40,164	0
Dividends paid	(6,785)	(4,655)
Repayments of short-term debt	0	(970)
Repurchase of common stock	0	(229)
Net cash provided by financing activities	54,020	341,974
Net increase in cash and cash equivalents	5,370	7,907
Cash and cash equivalents, beginning of period	20,018	12,412
Cash and cash equivalents, end of period	25,388	20,319
Supplemental cash flow information
Cash payments for interest	979	378
Cash payments for taxes	$ 0	$ 115