Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended		5 Months Ended	7 Months Ended	12 Months Ended			13 Months Ended	15 Months Ended
	Mar. 31, 2013	Sep. 30, 2012	Sep. 30, 2013	Mar. 31, 2013	Jul. 31, 2013	Mar. 31, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013	Jul. 31, 2013	Sep. 30, 2013	Aug. 01, 2013
Class of Stock [Line Items]
Shares Paid for Tax Withholding for Share Based Compensation							205,842
Treasury Stock, Value, Acquired, Cost Method									$ 197.6
Percent of advance payment under accelerated share repurchase agreement								80.00%
September 2012 Accelerated Share Repurchase [Member]
Class of Stock [Line Items]
Treasury Stock, Value, Acquired, Cost Method						$ 50.0			50.0
Treasury Stock, Shares, Acquired		1,328,462		234,898		1,563,360
Treasury Stock Acquired, Average Cost Per Share						$ 31.98
March 2013 Accelerated Share Repurchase [Member]
Class of Stock [Line Items]
Treasury Stock, Value, Acquired, Cost Method					$ 50.0				$ 50.0
Treasury Stock, Shares, Acquired	1,044,932		101,247		1,146,179
Percent of advance payment under accelerated share repurchase agreement									80.00%
Treasury Stock Acquired, Average Cost Per Share					$ 43.62				$ 38.28
2012StockRepurchasePlan [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Remaining Authorized Repurchase Amount									$ 2.4
Stock repurchase program, authorized value												$ 200.0
Treasury Stock, Value, Acquired, Cost Method											$ 200.0
Treasury Stock, Shares, Acquired											5,458,285
Treasury Stock Acquired, Average Cost Per Share											$ 36.64
September Open Market Repurchases [Member]
Class of Stock [Line Items]
Treasury Stock, Value, Acquired, Cost Method									50.0
Open Market Repurchases [Member]
Class of Stock [Line Items]
Treasury Stock, Value, Acquired, Cost Method									$ 97.6	$ 100.0
Treasury Stock, Shares, Acquired			51,071						2,697,675	2,748,746
Treasury Stock Acquired, Average Cost Per Share									$ 36.17	$ 36.38
March Open Market Repurchases [Member]
Class of Stock [Line Items]
Treasury Stock, Value, Acquired, Cost Method									$ 50.0