Intangible Assets and Goodwill (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Summary of roll forward of the changes in goodwill
Goodwill, beginning of period	$ 1,146,314,000	$ 1,146,314,000
Goodwill acquired during the period	48,200,000	0
Other goodwill adjustments	6,800,000	0
Goodwill, end of period	$ 1,201,296,000	$ 1,146,314,000