Basic and Diluted Earnings per Share - Numerator and Denominator of the Basic and Diluted Per Share Computations for Earnings Attributable to Shareholders Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Net Earnings Attributable to Shareholders
Basic earnings attributable to shareholders	$ 83,824	$ 80,315
Diluted earnings attributable to shareholders	$ 83,824	$ 80,315
Weighted Average Shares
Weighted average basic shares outstanding	201,118,390	206,475,095
Effect of dilutive potential common shares	725,468	1,138,768
Weighted average diluted shares outstanding	201,843,858	207,613,863
Earnings Per Share
Basic earnings attributable to shareholders per share	$ 0.42	$ 0.39
Diluted earnings attributable to shareholders per share	$ 0.42	$ 0.39

Basic and Diluted Earnings per Share - Numerator and Denominator of the Basic and Diluted Per Share Computations for Earnings Attributable to Shareholders Per Share (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified

3 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Net Earnings Attributable to Shareholders

Basic earnings attributable to shareholders

$ 83,824

$ 80,315

Diluted earnings attributable to shareholders

$ 83,824

$ 80,315

Weighted Average Shares

Weighted average basic shares outstanding

201,118,390

206,475,095

Effect of dilutive potential common shares

725,468

1,138,768

Weighted average diluted shares outstanding

201,843,858

207,613,863

Earnings Per Share

Basic earnings attributable to shareholders per share

$ 0.42

$ 0.39

Diluted earnings attributable to shareholders per share

$ 0.42

$ 0.39

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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