Face (par) amount of debt instrument at time of issuance.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Convertible Debentures and Credit Arrangements - Convertible Senior Debentures due 2014 Narrative (Details) (Convertible Senior Debentures due 2014 [Member], USD $)	Mar. 31, 2014	Nov. 30, 2012	Dec. 31, 2010
Convertible Senior Debentures due 2014 [Member]
Debt Instrument [Line Items]
Face amount			$ 46,900,000.0
Repurchase amount		58,700,000
Debt Instrument, Convertible, Principal Converted to Common Stock	$ 29,000