Shareholders' Equity (Narrative) (Details) $ in Millions	Jan. 31, 2017 USD ($)
December 2014 Program
Equity, Class of Treasury Stock
Share repurchase authorized amount	$ 100.0
June 2015 Program
Equity, Class of Treasury Stock
Share repurchase authorized amount	$ 100.0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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