The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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)(1)(iv)(3)

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

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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)(iii)(1)

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

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

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

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ 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

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Stockholders' Equity - Activities Under Equity Plan (Detail)	34 Months Ended	0 Months Ended	3 Months Ended
	Mar. 31, 2015	Jan. 01, 2015	Mar. 31, 2015	May 16, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity securities available at May 16, 2012				2,194,986
Total equity securities available at March 31, 2015	1,487,484		1,487,484
Short-Term Incentive Plan ("STIP") [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Less: Equity Plan shares awarded	(41,702)
Restricted Stock Units [Member] \| 2011 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Add: 2011 LTIP RSUs forfeited by eligible employees	209,382
Less: Equity Plan shares awarded	(557,484)
Restricted Stock Units [Member] \| 2015 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Add: 2011 LTIP RSUs forfeited by eligible employees			0
Less: Equity Plan shares awarded	(254,777)	(254,777)	(254,777)
Restricted Stock [Member] \| Non-executive directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Add: 2011 LTIP RSUs forfeited by eligible employees	3,189
Less: Equity Plan shares awarded	(60,290)
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Less: Equity Plan shares awarded	(5,820)
Common Stock [Member] \| 2015 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Less: Equity Plan shares awarded		(254,777)