CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Residential mortgage investments	$ 13,480,000	$ 13,120,000
Preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized (in shares)	100,000us-gaap_PreferredStockSharesAuthorized	100,000us-gaap_PreferredStockSharesAuthorized
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	250,000us-gaap_CommonStockSharesAuthorized	250,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued (in shares)	95,848us-gaap_CommonStockSharesIssued	95,807us-gaap_CommonStockSharesIssued
Common stock, shares outstanding (in shares)	95,848us-gaap_CommonStockSharesOutstanding	95,807us-gaap_CommonStockSharesOutstanding
Redeemable Preferred Stock [Member] \| Cumulative Redeemable Preferred Stock, Series E [Member]
Preferred stock, dividend rate (in hundredths)	7.50%
Preferred stock, shares issued (in shares)	7,618	6,861
Preferred stock, shares outstanding (in shares)	7,618	6,861
Preferred stock, aggregate liquidation preference	$ 190,454	$ 171,521

Face amount or stated value per share of common stock.

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