Reconciliation of Weighted Average Shares Used in Calculating Basic and Diluted Earnings Per Share (Detail) - shares shares in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share Disclosure [Line Items]
Basic	48,293	48,431	56,281
Effect of assuming vesting of performance related to restricted stock-based awards		212	199
Effect of convertible notes subject to conversion		6,565	1,685
Diluted	48,293	57,366	60,734
Stock Options
Earnings Per Share Disclosure [Line Items]
Effect of exercise of stock options		804	1,137
Restricted Stock
Earnings Per Share Disclosure [Line Items]
Effect of exercise of stock options		1,354	1,432

Earnings Per Share Disclosure [Line Items]

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- Definition

Incremental common shares attributable to performance shares.

+ References

No definition available.

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- Definition

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible debt securities using the if-converted method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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-Section 45
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-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1930-109256

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- Definition

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
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- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=6528421

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