Related Party Transactions and Arrangements (Merger and Other Non-Routine Transactions) (Detail) (Affiliated Entity [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 490,519	$ 244,435	$ 20,260
Strategic Advisory Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	36,096
Merger Related Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	3,666
Merger Related Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	3,573
Merger Related Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	890
Subordinated Distributions [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	98,360
Furniture, Fixtures And Equipment [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	5,800
Other Non-Routine Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	950
Other Non-Routine Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	2,679
Post Transaction Support Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	4,000
Other Non Routine Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	132
Merger And Acquisition Related Costs [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	156,146
ARCT III Merger [Member] | Strategic Advisory Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
ARCT III Merger [Member] | Merger Related Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	126
ARCT III Merger [Member] | Merger Related Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	522
ARCT III Merger [Member] | Merger Related Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
ARCT III Merger [Member] | Subordinated Distributions [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	98,360
ARCT III Merger [Member] | Furniture, Fixtures And Equipment [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	5,800
ARCT III Merger [Member] | Other Non-Routine Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	950
ARCT III Merger [Member] | Other Non-Routine Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
ARCT III Merger [Member] | Post Transaction Support Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	2,000
ARCT III Merger [Member] | Other Non Routine Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
ARCT III Merger [Member] | Merger And Acquisition Related Costs [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	107,758
ARCT IV Merger [Member] | Strategic Advisory Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	16,075
ARCT IV Merger [Member] | Merger Related Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	500
ARCT IV Merger [Member] | Merger Related Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	2,137
ARCT IV Merger [Member] | Merger Related Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	640
ARCT IV Merger [Member] | Subordinated Distributions [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
ARCT IV Merger [Member] | Furniture, Fixtures And Equipment [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
ARCT IV Merger [Member] | Other Non-Routine Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
ARCT IV Merger [Member] | Other Non-Routine Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	1,107
ARCT IV Merger [Member] | Post Transaction Support Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	2,000
ARCT IV Merger [Member] | Other Non Routine Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
ARCT IV Merger [Member] | Merger And Acquisition Related Costs [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	22,459
Cole Merger [Member] | Strategic Advisory Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	14,215
Cole Merger [Member] | Merger Related Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Cole Merger [Member] | Merger Related Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	169
Cole Merger [Member] | Merger Related Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Cole Merger [Member] | Subordinated Distributions [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Cole Merger [Member] | Furniture, Fixtures And Equipment [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Cole Merger [Member] | Other Non-Routine Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Cole Merger [Member] | Other Non-Routine Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	1,463
Cole Merger [Member] | Post Transaction Support Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Cole Merger [Member] | Other Non Routine Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Cole Merger [Member] | Merger And Acquisition Related Costs [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	15,847
CapLease Acquisition [Member] | Strategic Advisory Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	5,563
CapLease Acquisition [Member] | Merger Related Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	3,000
CapLease Acquisition [Member] | Merger Related Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	567
CapLease Acquisition [Member] | Merger Related Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	250
CapLease Acquisition [Member] | Subordinated Distributions [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
CapLease Acquisition [Member] | Furniture, Fixtures And Equipment [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
CapLease Acquisition [Member] | Other Non-Routine Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
CapLease Acquisition [Member] | Other Non-Routine Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
CapLease Acquisition [Member] | Post Transaction Support Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
CapLease Acquisition [Member] | Other Non Routine Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	132
CapLease Acquisition [Member] | Merger And Acquisition Related Costs [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	9,512
Other Acquisitions [Member] | Strategic Advisory Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	243
Other Acquisitions [Member] | Merger Related Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	40
Other Acquisitions [Member] | Merger Related Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	178
Other Acquisitions [Member] | Merger Related Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Other Acquisitions [Member] | Subordinated Distributions [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Other Acquisitions [Member] | Furniture, Fixtures And Equipment [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Other Acquisitions [Member] | Other Non-Routine Costs, Legal Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Other Acquisitions [Member] | Other Non-Routine Costs, Personnel Costs And Other Reimbursements [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	109
Other Acquisitions [Member] | Post Transaction Support Services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Other Acquisitions [Member] | Other Non Routine Costs Other Fees And Expenses [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0
Other Acquisitions [Member] | Merger And Acquisition Related Costs [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 570