Fair Value of Financial Instruments - Equity Interest in Ernest and Related Loans Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	$ 200,750us-gaap_InvestmentOwnedAtFairValue
Cost	200,750us-gaap_InvestmentOwnedAtCost
Fair Value Measurements, Recurring [Member] \| Acquisition loans [Member] \| Other loans [Member]
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	97,450
Cost	97,450
Fair Value Measurements, Recurring [Member] \| Equity investments [Member] \| Other assets [Member]
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	3,300
Cost	3,300
Fair Value Measurements, Recurring [Member] \| Mortgage loans [Member] \| Mortgage loans [Member]
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	100,000
Cost	$ 100,000

Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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Reference 10: http://www.xbrl.org/2003/role/presentationRef

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Reference 11: http://www.xbrl.org/2003/role/presentationRef

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Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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+ Details