The percentage of a participant's voluntary contribution the Company will match.

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Compensation plan of voluntary contribution addition

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The maximum defined contribution compensation expense recognized during the period.

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Number Of Years For Average Long Term Investment Capital

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Percentage Of Average Long Term Investment Capita

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Percentage Of Performance-Based Awards Granted

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Performance threshold multiplier, basis points.

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Spread Over Ten Year US Treasury Rate

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The number of shares originally issued under a share based award plan pertaining to grants outstanding during the period on other than stock option plans (for example, phantom stock plan, stock appreciation rights plan, performance target plan).

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Weighted average remaining contractual term as of the balance sheet date for those share-based payment arrangements exercisable and outstanding.

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Aggregate number of common shares reserved for future issuance.

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

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Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding.

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As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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The aggregate amount of expenditures for salaries, wages, profit sharing and incentive compensation, and other employee benefits, including equity-based compensation, and pension and other postretirement benefit expense.

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-SubTopic 10

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-Subparagraph (SX 210.5-03.4)

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Other generally recurring costs associated with normal operations excluding those directly related to the marketing or selling of products and services not otherwise defined.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Date the equity-based award expires, in CCYY-MM-DD format.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of fully vested and expected to vest options that are exercisable.

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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Compensation Programs (Narrative) (Detail) (USD $)	3 Months Ended		6 Months Ended
Compensation Programs (Narrative) (Detail) (USD $)	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Share Based Compensation Programs [Line Items]
Expiration date of grant			Jul. 01, 2015
Common shares for future issuance	831,668		831,668
Percentage of performance-based awards granted			50.00%
Share awards vesting period (in years)			1 year
Salaries and benefits	$ 1,682,000	$ 1,672,000	$ 3,509,000	$ 3,373,000
Common stock dividend payable	39,427,000		39,427,000		38,184,000
2012 [Member]
Share Based Compensation Programs [Line Items]
Total grants			72,000
Other Benefit Programs [Member]
Share Based Compensation Programs [Line Items]
Salaries and benefits	117,000		250,000
Compensation plan of voluntary contribution			50.00%
Compensation plan of voluntary contribution, maximum			6.00%
Compensation plan of voluntary contribution, additional			3.00%
Performance-Based Stock Awards Vesting In Three Year [Member]
Share Based Compensation Programs [Line Items]
Percentage of performance-based awards granted			50.00%
Performance-Based Stock Awards Vesting After Three Year [Member]
Share Based Compensation Programs [Line Items]
Share awards vesting period (in years)			3 years
Long-Term Equity-Based Awards [Member]
Share Based Compensation Programs [Line Items]
Percentage of investment capital, maximum			8.00%
Number of years for average long-term investment capital			10
Spread over 10-year U.S. Treasury rate (basis points)			2.00%
Share awards vesting period (in years)			3 years
Stock Options
Share Based Compensation Programs [Line Items]
Share awards vesting period (in years)			10 years
Weighted average remaining contractual term (in years)			5.0
Exercisable option awards outstanding	220,000		220,000
Weighted average exercise price	$ 10.82		$ 10.82
Aggregate intrinsic value of stock options	686,000		686,000
Intrinsic value of option awards exercised			125,000
Annual Incentive Compensation [Member]
Share Based Compensation Programs [Line Items]
Percentage of investment capital, maximum			10.00%
Number of years for average long-term investment capital			10
Spread over 10-year U.S. Treasury rate (basis points)			2.00%
Performance threshold multiplier, basis points			0.50%
Stock Awards Activity [Member]
Share Based Compensation Programs [Line Items]
Salaries and benefits			468,000	937,000
Other general and administrative expense			81,000	161,000
Common stock dividend payable	549,000		549,000
Total of Unrecognized compensation expense for unvested stock award	$ 4,000,000		$ 4,000,000
Weighted average remaining contractual term (in years)			1.6