Summary of Investments in Real Estate (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Real Estate Properties [Line Items]
Land	$ 30,168	$ 30,168	$ 27,089
Building	121,390	121,390	109,072
Furniture, fixtures and equipment	2,159	2,007	1,267
Total investment in real estate	153,717	153,565	137,428
Accumulated depreciation	(13,110)	(12,283)	(9,304)
Investments in real estate, net	$ 140,607	$ 141,282	$ 128,124

Amount before accumulated depreciation of building structures held for productive use including addition, improvement, or renovation to the structure, including, but not limited to, interior masonry, interior flooring, electrical, and plumbing.

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-Publisher AICPA

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Gross amount of fixtures and equipment as of the date of the statement of financial position. Fixtures may include and consist of: machinery, equipment, engines, boilers, incinerators, installed building materials; systems and equipment for the purpose of supplying or distributing heating, cooling, electricity, gas, water, air, or light; antennas, cable, wiring and conduits used in connection with radio, television, security, fire prevention, or fire detection or otherwise used to carry electronic signals; telephone systems and equipment; elevators and related machinery and equipment; fire detection, prevention and extinguishing systems and apparatus; security and access control systems and apparatus; plumbing systems; water heaters, ranges, stoves, microwave ovens, refrigerators, dishwashers, garbage disposers, washers, dryers and other appliances; light fixtures, awnings, storm windows and storm doors; pictures, screens, blinds, shades, curtains and curtain rods; mirrors; cabinets, paneling, rugs and floor and wall coverings; fences, trees and plants; swimming pools; and such other items as defined by the reporting entity.

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Carrying amount as of the balance sheet date of real estate held for productive use. This excludes land held for sale.

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The amount of accumulated depreciation for the property as of the balance sheet date.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

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-Article 5

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Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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