Shareholders' Equity Reconciliation of Weighted Average Number of Shares (Detail) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Weighted Average Number of Shares Outstanding [Line Items]
Weighted average number of common shares outstanding	68,209	68,409	68,315
Director Plan and deferred stock units	242	341	342
ESOP	84	99	135
Common shares outstanding—basic	68,535	68,849	68,792
Common and potential common shares outstanding—diluted	70,546	71,005	71,057
Restricted Stock [Member]
Weighted Average Number of Shares Outstanding [Line Items]
Dilutive effect of stock awards	228	181	165
Stock Options [Member]
Weighted Average Number of Shares Outstanding [Line Items]
Dilutive effect of stock awards	1,783	1,975	2,100

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.

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This element represents the weighted average total number of shares issued throughout the period including the first (beginning balance outstanding) and last (ending balance outstanding) day of the period before considering any reductions (for instance, shares held in treasury) to arrive at the weighted average number of shares outstanding. Weighted average relates to the portion of time within a reporting period that common shares have been issued and outstanding to the total time in that period. Such concept is used in determining the weighted average number of shares outstanding for purposes of calculating earnings per share (basic).

+ References

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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

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-Glossary Weighted-Average Number of Common Shares Outstanding

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

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