Computation of Earnings per Common Share (Details) (USD $) In Thousands, except Share data	3 Months Ended
Jun. 30, 2011	Jun. 30, 2010
BASIC EARNINGS PER SHARE [Abstract]
Numerator: Net income	$ 16,985	$ 12,645
Denominator:
Weighted-average common shares outstanding	218,200	224,538
Basic earnings per share	$ 0.08	$ 0.06
DILUTED EARNINGS PER SHARE [Abstract]
Numerator: Net income	$ 16,985	$ 12,645
Denominator:
Weighted-average common shares outstanding	218,200	224,538
Dilutive effect of stock awards	4,748	3,037
Total shares	222,948	227,575
Diluted earnings per share	$ 0.08	$ 0.06
Anti-dilutive shares related to stock awards excluded from EPS calculation (in shares)	5,100,000	20,100,000

Calculation of denominator for basic EPS.

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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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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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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