Business and Summary of Significant Accounting Principles (Narratives) (Details) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended
	Jul. 22, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Business
Year founded				1997
Acquisition
Purchase of business	$ 100,000,000			$ 100,000,000	$ 0
Goodwill		215,384,000		215,384,000		77,294,000
Revenue Recognition
Revenues		220,427,000	178,494,000	596,304,000	526,505,000
Receivables		202,287,000		202,287,000		150,436,000
Percentage phase down				20.00%
Percentage phase down, maximum				60.00%
Total High Cost Support Program [Member]
Revenue Recognition
Revenues		14,900,000	10,700,000	36,000,000	31,800,000
Receivables		46,800,000		46,800,000
ACS [Member]
Acquisition
Purchase of business	100,000,000
Percentage of ownership	33.30%
Preferential cash distributions	190,000,000
Preference period	4 years
Preferential adjustment				21,800,000
Additional revenue		27,700,000		27,700,000
Transaction costs		4,600,000		4,600,000		4,600,000
Goodwill	138,090,000
Selling, General and Administrative Expenses [Member] | ACS [Member]
Acquisition
Transaction costs		$ 1,600,000		$ 1,600,000