Acquisition of CapLease and Cole Acquisition of CapLease and Cole - Cole Acquisition Narrative (Detail) (USD $)	3 Months Ended				0 Months Ended	2 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Feb. 07, 2014	Mar. 31, 2014		Dec. 31, 2013
Business Acquisition [Line Items]
Amortization of intangible assets	$ 0	[1]	$ 0	[1]
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Goodwill	2,298,677,000	[2]				2,298,677,000	[2]	92,789,000	[2]
Cole Merger [Member]
Business Acquisition [Line Items]
Business combination, consideration transferred					7,467,643,000
Issuance of common stock					520,791,136
Real estate investments acquired					8,963,883,000
Below-market lease liabilities					212,433,000
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Amortization expense, remainder of 2014	72,600,000					72,600,000
Amortization expense, 2015	96,300,000					96,300,000
Amortization expense, 2016	96,300,000					96,300,000
Amortization expense, 2017	96,300,000					96,300,000
Amortization expense, 2018	9,800,000					9,800,000
Goodwill					2,212,920,000
Revenue of acquiree since acquisition date						162,600,000
Earnings or loss of acquiree since acquisition date						700,000
Cole Merger [Member] | Management And Advisory Contracts [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life	4 years
Amortization of intangible assets	14,000,000
Real Estate Investment Segment [Member]
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Goodwill	1,739,842,000					1,739,842,000		92,789,000
Real Estate Investment Segment [Member] | Cole Merger [Member]
Business Acquisition [Line Items]
Real estate investments acquired					8,963,883,000
Below-market lease liabilities					212,433,000
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Goodwill					1,654,085,000
Private Capital Management Segment [Member] | Cole Merger [Member]
Business Acquisition [Line Items]
Real estate investments acquired					0
Below-market lease liabilities					0
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Goodwill	$ 558,800,000				$ 558,835,000	$ 558,800,000

[1] These five depreciation and amortization line item captions have been consolidated into one line item caption named depreciation and amortization in the accompanying consolidated statements of cash flows.

[2] For discussion on the restatement adjustments, see Note 2 - Restatement of Previously Issued Financial Statements.