Variable Interest Entities VIEs (Details) (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 409,579,000	$ 183,101,000	$ 378,358,000	$ 424,155,000
Other current assets		19,051,000	16,745,000
Licenses	1,531,873,000	1,397,888,000	1,456,794,000	1,470,769,000
Property, plant and equipment, net		2,874,593,000	3,022,588,000
Other assets and deferred charges		95,709,000	78,148,000
Liabilities
Current liabilities		852,380,000	754,999,000
Capital contributions and advances	5,000,000
Variable Interest Entities (VIE's)
Assets
Cash and cash equivalents		2,669,000	5,849,000
Other current assets		1,190,000	120,000
Licenses		308,091,000	308,091,000
Property, plant and equipment, net		17,535,000	16,443,000
Other assets and deferred charges		541,000	887,000
Total assets		330,026,000	331,390,000
Liabilities
Current liabilities		3,000	1,013,000
Deferred liabilities and credits		3,280,000	3,024,000
Total liabilities		$ 3,283,000	$ 4,037,000