Stockholders' Equity Repurchases of Common Stock (Details) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended
Dec. 11, 2013	Nov. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2012
Stockholders' Equity Note [Abstract]
Treasury stock, shares acquired	600,000us-gaap_TreasuryStockSharesAcquired	256,262us-gaap_TreasuryStockSharesAcquired		873,146us-gaap_TreasuryStockSharesAcquired	600,000us-gaap_TreasuryStockSharesAcquired	1,129,408us-gaap_TreasuryStockSharesAcquired
Treasury stock acquired, average price paid per share	$ 13.18	$ 21.58	$ 24.26		$ 23.65
Stock repurchase program, remaining authorized repurchase amount			$ 0	$ 0		$ 0

Number of shares that have been repurchased during the period and are being held in treasury.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

Name:	us-gaap_TreasuryStockSharesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration