Common Stock and Stock-based Compensation (Details) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of the changes in the number of shares of common stock issued
Number of Common Stock Shares Issued, Beginning balance	27,164us-gaap_CommonStockSharesIssued	27,050us-gaap_CommonStockSharesIssued	27,024us-gaap_CommonStockSharesIssued
Exercise of stock options and SARs	62	114	26
Number of Common Stock Shares Issued, Ending balance	27,226us-gaap_CommonStockSharesIssued	27,164us-gaap_CommonStockSharesIssued	27,050us-gaap_CommonStockSharesIssued

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant