Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended			12 Months Ended
	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011 California Franchise Tax Board [Member]	Dec. 31, 2010 California Franchise Tax Board [Member]	Dec. 31, 2009 California Franchise Tax Board [Member]	Dec. 31, 2007 California Franchise Tax Board [Member]	Dec. 31, 2006 California Franchise Tax Board [Member]	Dec. 31, 2005 California Franchise Tax Board [Member]	Dec. 31, 2011 Internal Revenue Service (IRS) [Member]	Dec. 31, 2010 Internal Revenue Service (IRS) [Member]	Dec. 31, 2009 Internal Revenue Service (IRS) [Member]	Dec. 31, 2010 Canada Revenue Agency [Member]	Dec. 31, 2009 Canada Revenue Agency [Member]	Dec. 31, 2008 Canada Revenue Agency [Member]
Income Taxes [Line Items]
U.S. federal statutory rate		35.00%
Effective income tax rate	24.70%
Income before income taxes, domestic operations		$ 33.2	$ 27.7
Income before income taxes, foreign operations		42.9	50.0
Liabilities for uncertain income tax positions	41.2	41.2		37.7
Cash paid for income taxes		14.1
Prepaid tax payments	$ 9.4	$ 9.4		$ 9.0
Income Tax Examination, Year under Examination					2011	2010	2009	2007	2006	2005	2011	2010	2009	2010	2009	2008