Stockholders' Equity - Stockholders' Equity (Detail)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Common Stock, Beginning balance	29,554,500us-gaap_CommonStockSharesIssued	29,555,000us-gaap_CommonStockSharesIssued	29,555,000us-gaap_CommonStockSharesIssued
Treasury Stock, Beginning balance	5,208,000us-gaap_TreasuryStockNumberOfSharesHeld	6,222,000us-gaap_TreasuryStockNumberOfSharesHeld	6,507,000us-gaap_TreasuryStockNumberOfSharesHeld
Exercise of options, Common Stock	0	0	0
Exercise of options, Treasury Stock	(105,000)	(632,000)	(333,000)
Acquisition-related stock issued, Common Stock	0	0	0
Acquisition-related stock issued, Treasury Stock	0	(471,000)	0
Stock purchases, Common Stock	0	0	0
Stock purchases, Treasury Stock	160,000us-gaap_TreasuryStockSharesAcquired	89,000us-gaap_TreasuryStockSharesAcquired	48,000us-gaap_TreasuryStockSharesAcquired
Common Stock, Ending balance	29,554,500us-gaap_CommonStockSharesIssued	29,554,500us-gaap_CommonStockSharesIssued	29,555,000us-gaap_CommonStockSharesIssued
Ending balance, Treasury Stock	5,263,000us-gaap_TreasuryStockNumberOfSharesHeld	5,208,000us-gaap_TreasuryStockNumberOfSharesHeld	6,222,000us-gaap_TreasuryStockNumberOfSharesHeld

Treasury Stock Issued During Period Shares Share Based Compensation Gross

No definition available.

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- Definition

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.

+ References

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

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

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Period Type:	duration

- Definition

Number of shares of stock issued during the period pursuant to acquisitions.

+ References

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 S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.28,29)

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

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

+ Details

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

- Definition

Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

+ References

No definition available.

+ Details

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- Definition

Number of treasury shares (units) reissued during the period, excluding reissuance of shares (units) held in treasury used to satisfy equity-based compensation obligations exercised by the holders of such rights. Upon reissuance of shares (units) from treasury, either the common or preferred stock (unit) reissued is outstanding.

+ References

+ Details

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

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
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- Definition

Number of shares held for each class of treasury stock.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

+ Details

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

- Definition

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

+ References

+ Details

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