Derivative Financial Instruments (Executed interest rate swap) (Details) (Interest Rate Swap, USD $) In Millions, unless otherwise specified	Apr. 20, 2011	Mar. 31, 2014 Cash Flow Hedges transaction	Dec. 31, 2009 Cash Flow Hedges transaction	Mar. 31, 2014 Cash Flow Hedges New Contracts transaction
Derivative [Line Items]
Derivative, notional amount	$ 15.0	$ 85.0		$ 16.6
Number of swap transactions		5	3	2

Number of interest rate derivative instruments held by the entity at the reporting date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959

Name:	us-gaap_NumberOfInterestRateDerivativesHeld
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant