Real Estate - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended					12 Months Ended		1 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended				12 Months Ended		12 Months Ended	1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended					1 Months Ended		12 Months Ended		1 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jul. 01, 2011 acre	Jan. 19, 2011	Dec. 31, 2011 Predecessor	Dec. 31, 2010 Predecessor	Dec. 31, 2012 160 King Street	Dec. 31, 2011 Formation Transactions	Dec. 31, 2012 Beach Street Property sqft	Dec. 31, 2012 Beach Street Property sqft	Dec. 31, 2012 City Center Store sqft	Dec. 31, 2012 Geary Marketplace sqft	Dec. 31, 2011 Waikiki Beach Walk Entities Predecessor	Dec. 31, 2011 Waikiki Beach Walk Entities Formation Transactions	Dec. 31, 2011 Solana Beach Centre Entities Predecessor	Dec. 31, 2011 Solana Beach Centre Entities Formation Transactions	Mar. 31, 2011 First & Main	Dec. 31, 2011 First & Main	Mar. 11, 2011 First & Main sqft	Jul. 31, 2011 Lloyd District Portfolio Building sqft Property	Dec. 31, 2011 Lloyd District Portfolio	Jul. 01, 2011 Lloyd District Portfolio sqft Property	Jul. 01, 2011 Lloyd District Portfolio Condominiums	Jul. 01, 2011 Lloyd District Portfolio Lloyd Seven Hundred Building	Jul. 01, 2011 Lloyd District Portfolio Landmark Buildings Within Oregon Square	Dec. 14, 2011 Solana Beach Highway 101 Land acre	Sep. 20, 2011 Solana Beach Highway 101 Land acre	Dec. 31, 2011 Solana Beach Highway 101 Land	Dec. 31, 2011 First and Main Lloyd District Portfolio and Solana Beach Highway One Zero One	Aug. 31, 2011 Valencia Corporate Center
Real Estate Properties [Line Items]
Date of acquisition									Jan. 24, 2012
Rentable square feet of a specific real estate property																		97,000	97,000	497,000	35,000							361,000			610,000
Purchase price of a specific real estate property									$ 228,800,000									$ 36,500,000			$ 21,000,000					$ 128,900,000			$ 91,600,000						$ 1,300,000	$ 6,800,000
Number of stories in a real estate property																		3	3	27								16				20	16	4
Closing costs for a specific real estate property									100,000										20,000		20,000					100,000			100,000							200,000
Business acquisition, identifiable intangible assets and liabilities, weighted average life																			7 years	5 years 9 months 18 days	19 years 10 months 2 days		5 years 4 months 24 days		10 years 6 months		11 years 4 months 24 days			3 years 9 months 18 days							1 year 6 months
Approximate additional credits received to purchase price									6,900,000
Percentage of leased real estate property																					100.00%
Total revenue of specific real estate properties									10,217,000	8,617,000	2,583,000						57,700,000		3,900,000	7,000,000																		16,100,000
Operating expenses of specific real estate properties									163,560,000	146,442,000	75,326,000						48,000,000		1,000,000	1,600,000																		12,900,000
Operating income (loss)	20,247,000	18,206,000	16,641,000	16,812,000	14,182,000	14,427,000	12,969,000	14,765,000	71,906,000	56,343,000	42,422,000						9,700,000		2,900,000	5,400,000																		3,200,000
Net income	41,821,000	4,285,000	2,624,000	2,871,000	655,000	4,618,000	455,000	13,596,000	51,601,000	19,324,000	2,174,000			16,995,000	4,379,000		(6,800,000)		600,000	0																		1,100,000
Business acquisition, purchase price																	33,900,000
Percentage of noncontrolling ownership interest													25.00%									50.00%		80.00%
Gain on business acquisition																							41,600,000		4,800,000
Fair value of assets and liabilities acquired																						26,000,000		31,300,000
Historical cost of assets and liabilities acquired																						(15,600,000)		26,500,000
Acres of land acquired												16																							0.2	1.7
Business acquisition, number of office buildings																													6
Business acquisition, number of contiguous blocks																															4
Sales price of a specific real estate property																$ 93,800,000																							$ 31,000,000