Long-Term Debt Convertible Debt (Details) (Convertible Subordinated Debt [Member], Convertible Senior Subordinated Debentures February 2027 [Member], USD $)	3 Months Ended
Mar. 31, 2014	Dec. 31, 2013	Feb. 17, 2007
Convertible Subordinated Debt [Member] \| Convertible Senior Subordinated Debentures February 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount	$ (2,539,000)	$ (2,709,000)
Principal Amount			$ 135,000,000
Interest Rate	4.125%

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

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=6584090&loc=d3e28878-108400

Name:	us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant