The increase in the fair value of plan assets from contributions made by the employer.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Retirement Benefits Activity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended							12 Months Ended
	Mar. 31, 2014 Qualified Pension Benefits [Member]	Mar. 31, 2014 SERP Pension Benefits [Member]	Mar. 31, 2014 Other Benefit [Member]	Mar. 31, 2014 Subsidiaries [Member]	Dec. 31, 2014 Scenario, Forecast [Member] Qualified Pension Benefits [Member]	Dec. 31, 2014 Scenario, Forecast [Member] SERP Pension Benefits [Member]	Dec. 31, 2014 Scenario, Forecast [Member] Other Benefit [Member]	Dec. 31, 2014 Scenario, Forecast [Member] Subsidiaries [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent				1.00%				4.00%
Aggregate expected contributions					$ 12.0	$ 4.0	$ 0.4
Company Contribution	$ 3.0	$ 0.5	$ 0.2