Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating activities:
Net income	$ 16,476	$ 10,280
Adjustments to reconcile net income to cash provided by operating activities:
Increase in accrued interest receivable	(3,261)	(3,458)
Increase (decrease) in accrued interest payable	(468)	232
Provision for loan losses	60	250
Gain on sale of investments, net	(351)	0
Fair value adjustments, net	210	126
Amortization and depreciation	13,257	4,385
Stock-based compensation expense	453	95
Net change in other assets and other liabilities	(2,053)	2,042
Net cash and cash equivalents provided by operating activities	24,323	13,952
Investing activities:
Purchase of investments	(881,854)	(769,785)
Principal payments received on investments	117,231	84,366
(Increase) decrease in principal receivable on investments	4,418	(7,164)
Proceeds from sales of investments	49,569	0
Principal payments received on securitized mortgage loans	13,745	9,065
Other investing activities	(534)	(6)
Net cash and cash equivalents used in investing activities	(697,425)	(683,524)
Financing activities:
Borrowings under (repayment of) repurchase agreements, net	592,405	614,700
Principal payments on non-recourse collateralized financing	(38,781)	(1,138)
Proceeds from issuance of common stock	123,733	95,206
Dividends paid	(11,307)	(8,192)
Net cash and cash equivalents provided by (used in) financing activities	666,050	700,576
Net increase in cash and cash equivalents	(7,052)	31,004
Cash and cash equivalents at beginning of period	48,776	18,836
Cash and cash equivalents at end of period	41,724	49,840
Supplemental Disclosure of Cash Activities:
Cash paid for interest	$ 7,488	$ 4,305