Compensation Plans - Summary of Outstanding Equity Awards (Details) - shares	Sep. 30, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding	157,201	217,873
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	1,263,708	1,095,305
Leadership grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	356,242	405,826
Amended And Restated 2003 Annual And Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	1,263,708
Stock options outstanding	157,201
Amended And Restated 2003 Annual And Long-Term Incentive Plan \| Annual grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	943,146
Amended And Restated 2003 Annual And Long-Term Incentive Plan \| Sign-on grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	320,562
Amended And Restated 2003 Annual And Long-Term Incentive Plan \| Leadership grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	356,242

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

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

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

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