Credit Facilities (Details) (USD $)						3 Months Ended		3 Months Ended				3 Months Ended			3 Months Ended			3 Months Ended										3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Feb. 14, 2013 Revolving Credit Facility [Member]	Mar. 31, 2014 Senior Revolving Credit Facility [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Fair Value, Inputs, Level 3 [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Minimum [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Maximum [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Line of Credit [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Line of Credit [Member] Fair Value, Inputs, Level 3 [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Line of Credit [Member] Minimum [Member] LIBOR [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Line of Credit [Member] Maximum [Member] LIBOR [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Term Loan [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Term Loan [Member] Minimum [Member] LIBOR [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Term Loan [Member] Maximum [Member] LIBOR [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Revolving Credit Facility [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Revolving Credit Facility [Member] Minimum [Member] Applicable Rate [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Revolving Credit Facility [Member] Maximum [Member] Applicable Rate [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Variable Interest Rate [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Senior Corporate Credit Facility [Member] Fixed Rate Line of Credit [Member]	Mar. 31, 2014 Unsecured Debt [Member] Revolving Credit Facility [Member] Fair Value, Inputs, Level 3 [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2013 Unsecured Debt [Member] Revolving Credit Facility [Member] Fair Value, Inputs, Level 3 [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Mar. 31, 2014 Unsecured Debt [Member] Regions Bank Unsecured Credit Facility [Member] Line of Credit [Member] ARCT IV / ARCP Merger [Member]	Mar. 31, 2014 Unsecured Debt [Member] Regions Bank Unsecured Credit Facility [Member] Term Loan [Member] ARCT IV / ARCP Merger [Member]	Mar. 31, 2014 Unsecured Debt [Member] Regions Bank Unsecured Credit Facility [Member] Revolving Credit Facility [Member] ARCT IV / ARCP Merger [Member]	Mar. 31, 2014 Unsecured Debt [Member] Wells Fargo, National Association, Unsecured Credit Facility [Member] Line of Credit [Member]	Mar. 31, 2014 Unsecured Debt [Member] Wells Fargo, National Association, Unsecured Credit Facility [Member] Line of Credit [Member] LIBOR [Member]
Line of Credit Facility [Line Items]
Outstanding Loan Amount	$ 4,234,668,000	$ 1,301,114,000								$ 2,950,000,000
Line of credit facility, amount outstanding														940,000,000			1,325,800,000			1,325,800,000	940,000,000			760,000,000	300,000,000	460,000,000	150,000,000
Line of credit facility, current borrowing capacity																	2,000,000,000										150,000,000
Debt instrument, basis spread on variable rate												2.25%	3.00%		1.15%	2.00%		0.90%	1.75%									2.75%
Line of credit facility, undrawn commitment										700,000,000
Line of credit facility, commitment fee percentage								0.15%	0.25%
Senior secured revolving credit facility			10,318,898,000	4,348,209,000			1,819,800,000				2,265,800,000											150,000,000	150,000,000
Debt instrument, interest rate, stated percentage																				3.15%
Line of credit, amount bearing fixed interest rate, percentage										2.54%
Line of credit facility, maximum borrowing capacity										700,000,000
Debt instrument, face amount																								800,000,000
Extinguishment of debt, amount						$ 124,600,000
Effective interest rate					3.11%