Fair Value of Financial Instruments (Schedule of Interest Rate Swaps) (Details) - Jun. 30, 2015 - Interest Rate Swap [Member] - USD ($)		Total
Interest Rate Swaps One [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 300,000,000
Fixed Interest Rate		3.447%
Termination Date		Aug. 06, 2016
Fair Value of Liability		$ 10,000,000
Interest Rate Swaps Two [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 100,000,000
Fixed Interest Rate		3.401%
Termination Date		Aug. 19, 2016
Fair Value of Liability		$ 3,000,000
Interest Rate Swaps Three [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 200,000,000
Fixed Interest Rate		3.429%
Termination Date		Aug. 19, 2016
Fair Value of Liability		$ 6,000,000
Interest Rate Swaps Four [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 200,000,000
Fixed Interest Rate		3.50%
Termination Date		Aug. 30, 2016
Fair Value of Liability		$ 7,000,000
Interest Rate Swaps Five [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 100,000,000
Fixed Interest Rate		3.005%
Termination Date		Nov. 30, 2016
Fair Value of Liability		$ 3,000,000
Interest Rate Swaps Six [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 200,000,000
Fixed Interest Rate		2.055%
Termination Date		Jul. 25, 2019
Fair Value of Liability		$ 4,000,000
Interest Rate Swaps Seven [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 200,000,000
Fixed Interest Rate		2.059%
Termination Date		Jul. 25, 2019
Fair Value of Liability		$ 4,000,000
Interest Rate Swaps Eight [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 400,000,000
Fixed Interest Rate		1.882%
Termination Date		Aug. 30, 2019
Fair Value of Liability	[1]
Interest Rate Swaps Nine [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 200,000,000
Fixed Interest Rate		2.515%
Termination Date		Aug. 30, 2019
Fair Value of Liability	[1]	$ 5,000,000
Interest Rate Swaps Ten [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 200,000,000
Fixed Interest Rate		2.613%
Termination Date		Aug. 30, 2019
Fair Value of Liability	[2]	$ 6,000,000
Interest Rate Swaps Eleven [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 300,000,000
Fixed Interest Rate		2.041%
Termination Date		Aug. 30, 2020
Fair Value of Liability	[1]
Interest Rate Swaps Twelve [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 300,000,000
Fixed Interest Rate		2.738%
Termination Date		Aug. 30, 2020
Fair Value of Liability	[1]	$ 9,000,000
Interest Rate Swaps Thirteen [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 300,000,000
Fixed Interest Rate		2.892%
Termination Date		Aug. 30, 2020
Fair Value of Liability	[2]	$ 11,000,000
Interest Rate Swaps Fourteen [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 300,000,000
Fixed Interest Rate		2.363%
Termination Date		Jan. 27, 2021
Fair Value of Liability	[3]	$ 1,000,000
Interest Rate Swaps Fifteen [Member]
Derivative [Line Items]
Notional Amount, Liability		$ 200,000,000
Fixed Interest Rate		2.368%
Termination Date		Jan. 27, 2021
Fair Value of Liability	[3]	$ 1,000,000

[1] This interest rate swap becomes effective August 28, 2015.

[2] This interest rate swap becomes effective August 30, 2015.

[3] This interest rate swap becomes effective February 29, 2016