Summary of Significant Accounting Policies (Derivatives) (Details) $ in Millions	Jun. 30, 2017 USD ($)
Cash Flow Hedging [Member] \| Interest rate swaps [Member]
Derivative [Line Items]
Derivative, amount of hedged items	$ 300.0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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