Lines of Credit and Financing Arrangements (Weighted Average Borrowing Rate) (Details)	Dec. 31, 2017	Dec. 31, 2016
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Weighted average borrowing rate (as a percent)	2.76%	2.00%

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.

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration