Income Taxes (Tax Returns Subject To Examination, By Jurisdiction) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
U.S. Federal [Member]
Liability for uncertain tax positions	0.1
Foreign [Member]
Liability for uncertain tax positions	0.2
Maximum [Member] | U.S. Federal [Member]
Period	2011
Maximum [Member] | U.S. State - Colorado [Member]
Period	2011
Maximum [Member] | Canada [Member]
Period	2011
Maximum [Member] | South Africa [Member]
Period	2009
Minimum [Member] | U.S. Federal [Member]
Period	2005
Minimum [Member] | U.S. State - Colorado [Member]
Period	2003
Minimum [Member] | Canada [Member]
Period	2005
Minimum [Member] | South Africa [Member]
Period	1999