Equity and Earnings Per Share (Computation Of Basic And Diluted Earnings Per Common Share) (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		5 Months Ended	6 Months Ended	9 Months Ended
	Mar. 20, 2017	Feb. 10, 2016	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Feb. 29, 2016	Mar. 31, 2017	Mar. 31, 2016	Oct. 26, 2016	Jun. 30, 2016	Sep. 14, 2015
Class of Stock [Line Items]
Unrealized Gain (Loss) on Derivatives and Commodity Contracts			$ 400				$ 20,700
Preferred Stock, Shares Authorized			5,000,000		5,000,000		5,000,000			5,000,000
Preferred Stock, Par or Stated Value Per Share			$ 0.01		$ 0.01		$ 0.01			$ 0.01
Preferred Stock, Shares Outstanding			0		0		0			0
Common Stock, Shares Authorized			150,000,000		150,000,000		150,000,000			150,000,000
Common Stock, Par or Stated Value Per Share			$ 0.01		$ 0.01		$ 0.01			$ 0.01
Common Stock, Shares, Outstanding			50,700,000		50,700,000		50,700,000			52,900,000
Disclosure of Repurchase Agreements [Abstract]
PercentOfSharesReceivedUnderASR							80.00%	80.00%
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Net income attributable to common stock			$ 17,800	$ 47,900			$ 77,400	$ 112,200
Weighted average number of shares outstanding, used in computing basic earnings per share			50,500,000	52,900,000			51,800,000	53,700,000
Dilutive common stock equivalents			700,000	700,000			800,000	800,000
Weighted average number of shares outstanding used in computing diluted earnings per share			51,200,000	53,600,000			52,600,000	54,500,000
Basic earnings per share			$ 0.35	$ 0.91			$ 1.49	$ 2.09
Diluted earnings per share			$ 0.35	$ 0.89			$ 1.47	$ 2.06
Anti-dilutive options (excluded from the calculation of diluted earnings per share)			700,000	1,700,000			700,000	1,300,000
FY2017StockRepurchasePlan [Member] [Domain] [Domain]
Disclosure of Repurchase Agreements [Abstract]
Stock Repurchase Program Authorized Amount									$ 200,000
Treasury Stock, Shares, Acquired	300,000				3,100,000			2,800,000
Accelerated Share Repurchases, Final Price Paid Per Share			$ 64.04
Treasury Stock, Value, Acquired, Cost Method			$ 200,000
Accelerated Share Repurchases, Initial Price Paid Per Share							$ 57.51
FY2016StockRepurchasePlan [Member] [Member] [Domain]
Disclosure of Repurchase Agreements [Abstract]
Stock Repurchase Program Authorized Amount											$ 200,000
Treasury Stock, Shares, Acquired		900,000				3,200,000		2,300,000
Accelerated Share Repurchases, Final Price Paid Per Share			$ 62.92
Accelerated Share Repurchases, Initial Price Paid Per Share								$ 70.35