Capital Stock	3 Months Ended
Apr. 30, 2011
Capital Stock And Share Repurchase [Abstract]
Capital Stock	5. Capital Stock On January 10, 2011, we entered into an accelerated share repurchase (ASR) agreement where we purchased 800,000 shares of our common stock from an investment bank at the closing price that day of $27.79 per share. The settlement and retirement of those shares occurred on January 11, 2011. Total consideration paid to purchase the shares of $22.2 million was recorded in “Stockholders' equity” as a reduction in “Common stock.” As part of the ASR, we simultaneously entered into a forward sale contract with the investment bank that was expected to mature in approximately 48 trading days, or March 18, 2011. Under the terms of the forward sale contract, the investment bank was required to purchase, in the open market, 800,000 shares of our common stock during the term of the contract to fulfill its obligation related to the shares it borrowed from third parties and sold to us. At settlement, we, at our option, were required to either pay cash or issue registered or unregistered shares of our common stock to the investment bank if the investment bank's weighted average purchase price, less a $.10 discount, was higher than the initial purchase closing price. The investment bank was required to pay us either cash or shares of our common stock, at our option, if the investment bank's weighted average price, less a $.10 discount, for the shares purchased was lower than the initial purchase closing price. At settlement on March 21, 2011, we paid cash of $.8 million to the investment bank and recorded this amount in “Stockholders' equity” as a reduction of “Common Stock” in the consolidated balance sheets. The $.8 million was the difference between the investment bank's weighted average purchase price of $28.8551 less a discount of $.10 for a settlement price of $28.7551 and the initial purchase closing price of $27.79 per share multiplied by 800,000 shares.

Capital Stock

3 Months Ended

Apr. 30, 2011

Capital Stock And Share Repurchase [Abstract]

5. Capital Stock

On January 10, 2011, we entered into an accelerated share repurchase (ASR) agreement where we purchased 800,000 shares of our common stock from an investment bank at the closing price that day of $27.79 per share. The settlement and retirement of those shares occurred on January 11, 2011. Total consideration paid to purchase the shares of $22.2 million was recorded in “Stockholders' equity” as a reduction in “Common stock.”

As part of the ASR, we simultaneously entered into a forward sale contract with the investment bank that was expected to mature in approximately 48 trading days, or March 18, 2011. Under the terms of the forward sale contract, the investment bank was required to purchase, in the open market, 800,000 shares of our common stock during the term of the contract to fulfill its obligation related to the shares it borrowed from third parties and sold to us. At settlement, we, at our option, were required to either pay cash or issue registered or unregistered shares of our common stock to the investment bank if the investment bank's weighted average purchase price, less a $.10 discount, was higher than the initial purchase closing price. The investment bank was required to pay us either cash or shares of our common stock, at our option, if the investment bank's weighted average price, less a $.10 discount, for the shares purchased was lower than the initial purchase closing price. At settlement on March 21, 2011, we paid cash of $.8 million to the investment bank and recorded this amount in “Stockholders' equity” as a reduction of “Common Stock” in the consolidated balance sheets. The $.8 million was the difference between the investment bank's weighted average purchase price of $28.8551 less a discount of $.10 for a settlement price of $28.7551 and the initial purchase closing price of $27.79 per share multiplied by 800,000 shares.