Supplemental Information (Credit Agreement) (Narrative) (Details) (Revolving Credit Facility [Member], USD $) In Millions, unless otherwise specified	7 Months Ended
	Apr. 30, 2013	Jun. 30, 2013
2013 Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Initiation date	Apr. 30, 2013
Maximum borrowing capacity	$ 2,500.0
Expiration date	Apr. 30, 2018
Borrowings outstanding		0
Length credit agreement in years	5 years
Iincrease in credit facility amount	330.0
2013 Credit Agreement [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Covenant, ratio of total debt to total capitalization	70.00%
Terminated 2010 Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Maximum borrowing capacity	2,170.0
Expiration date	Apr. 30, 2013
Original expiration date	Jun. 30, 2015
Borrowings outstanding	0
Early termination fees	$ 0
Terminated 2010 Credit Agreement [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Covenant, long-term debt divided by the sum of long-term debt plus equity	60.00%