Litigation and Other Events (Mining Claims) (Details) (Settlement of Mining Claims [Member], USD $) In Millions, unless otherwise specified	0 Months Ended	6 Months Ended
	Jun. 24, 2013	Jun. 30, 2013
Settlement of Mining Claims [Member]
Loss Contingencies [Line Items]
Cash payment	$ 10
NSR royalty percentage	3.40%	3.40%
NSR royalty maximum amount	39.4	39.4
NSR royalty fair value	$ 22.0