Earnings Per Share and Stock Repurchase Activity - Narrative (Details) (USD $)	Feb. 28, 2015
Earnings Per Share and Stock Repurchase Activity [Abstract]
Stock repurchase program, remaining authorized repurchase amount	$ 200,511,378
Stock repurchase program, authorized amount	$ 250,000,000

Amount remaining of a stock repurchase plan authorized.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant