Stock-Based Compensation (Details 8) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Non-Performance Based Stock Awards	Mar. 31, 2013 Stock option adjustment 2012	Sep. 30, 2013 Stock option adjustment 2012	Sep. 30, 2013 Subscriber-related	Sep. 30, 2012 Subscriber-related	Sep. 30, 2013 Subscriber-related	Sep. 30, 2012 Subscriber-related	Sep. 30, 2013 General and administrative	Sep. 30, 2012 General and administrative	Sep. 30, 2013 General and administrative	Sep. 30, 2012 General and administrative
Stock-Based Compensation
Non-cash, stock-based compensation	$ 10,552,000	$ 6,092,000	$ 25,328,000	$ 34,936,000		$ 4,000,000		$ 941,000	$ 312,000	$ 1,610,000	$ 1,506,000	$ 9,611,000	$ 5,780,000	$ 23,718,000	$ 33,430,000
Adjustment to recognized non-cash, stock-based compensation expense to be expensed over the remaining vesting period							3,000,000
Unrecognized compensation expense					$ 15,000,000
Future forfeiture rate (as a percent)					3.70%
Weighted average period for recognition of compensation cost					2 years