Summary of Significant Accounting Policies (Goodwill and Other Intangible Assets) (Details) - Customer Relationships	12 Months Ended
Dec. 31, 2017
Minimum
Goodwill and other intangible assets
Projected useful life	7 years
Maximum
Goodwill and other intangible assets
Projected useful life	15 years

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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