Schedule III - Real Estate and Accumulated Depreciation (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2013
Minimum [Member] | Office [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Real estate property useful life	30 years
Minimum [Member] | Building Improvements [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Real estate property useful life	5 years
Maximum [Member] | Office [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Real estate property useful life	40 years
Maximum [Member] | Building Improvements [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Real estate property useful life	20 years