Stock Compensation - Restricted Stock and Performance Share Grants - Summary of Stock Grant Activity (Details) (Stock Grants [Member])	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock Grants [Member]
Summary of stock grant activity:
Stock Grants Outstanding Beginning of the Year at Target Achievement	744,508	782,087	467,110
New Stock Grants/Additional shares due to maximum achievement	113,643	64,679	665,719
Vested Grants	(170,110)	(36,980)	(56,409)
Expired/Forfeited Grants	0	(65,278)	(294,333)
Stock Grants Outstanding December 31, 2012 at Target Achievement	688,041	744,508	782,087

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(a)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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