Derivative Instruments (Fair Value of Derivative Instruments on Balance Sheet) (Details) (Foreign currency forwards, USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Foreign currency forwards
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency forwards at fair value	$ 5.1	$ 12.8

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant