Income Taxes (Provision for Income Taxes Components) (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended							9 Months Ended		12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Provision for income taxes on income from continuing operations [Abstract]
Total provision for income tax	$ 31,000	$ 34,500	$ 17,800	$ 5,100	$ 37,000	$ 23,900	$ 17,200	$ 83,300	$ 78,100	$ 83,200	$ 104,400