Summary Of Significant Accounting Policies (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended						3 Months Ended		1 Months Ended
	Mar. 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May 31, 2014	Feb. 28, 2014	May 02, 2015	May 03, 2014	May 31, 2015	Jan. 31, 2015
Property, Plant and Equipment [Line Items]
Cash dividends declared per share (in dollars per share)		$ 0.235	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.235	$ 0.2
Stock split, conversion ratio	2
Other Long-term Assets [Member] | Restatement Adjustment [Member] | Accounting Standards Update 2015-03 [Member]
Property, Plant and Equipment [Line Items]
New accounting pronouncement, reclassification amount								$ 0.3		$ 2.8
Long-term Debt [Member] | Restatement Adjustment [Member] | Accounting Standards Update 2015-03 [Member]
Property, Plant and Equipment [Line Items]
New accounting pronouncement, reclassification amount								0.3		2.8
Property, Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment purchased but not yet paid							$ 18.0	$ 17.8
Subsequent Event [Member]
Property, Plant and Equipment [Line Items]
Cash dividends declared per share (in dollars per share)									$ 0.235