Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Description of the frequency of periodic payments (monthly, quarterly, annual).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount of the required periodic payments applied to principal.

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Amount of payment greater than the preceding installment payments to be paid at final maturity date of debt.

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The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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The cash inflow from amounts received from issuance of long-term debt that is wholly or partially secured by collateral. Excludes proceeds from tax exempt secured debt.

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Long-Term Debt - Nordea Credit Agreement (Details) - Nordea Q5000 Loan Maturing April 2020 [Member] - USD ($) $ in Millions	1 Months Ended		8 Months Ended
	Apr. 30, 2015	Sep. 30, 2014	Apr. 29, 2015	Jun. 30, 2015
Debt Instrument [Line Items]
Borrowing capacity		$ 250.0
Funded amount	$ 250.0
Commitment fee percentage			0.875%
Maturity date		Apr. 30, 2020
Scheduled principal installments		$ 8.9
Frequency of periodic payment		quarterly
Balloon payment		$ 80.4
Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Notional amount				$ 187.5
LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)		2.50%
Minimum [Member] \| Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Fixed LIBOR rate on interest rate swaps (as a percent)				1.49%
Maximum [Member] \| Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Fixed LIBOR rate on interest rate swaps (as a percent)				1.52%