Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 56,693	$ 15,584	$ 187
Additions	28,509	41,553	16,421
Deductions	(30,674)	(444)	(1,024)
Balance at End of Year	54,528	56,693	15,584
Reserve for program development costs [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	34,798	13,109	0
Additions	26,191	21,689	13,109
Deductions	(29,337)	0	0
Balance at End of Year	31,652	34,798	13,109
Allowance for doubtful accounts and other reserves [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	6,595	2,475	187
Additions	2,318	4,564	3,312
Deductions	(1,337)	(444)	(1,024)
Balance at End of Year	7,576	6,595	2,475
Unsecured note reserve [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	15,300	0
Additions	0	15,300
Deductions	0	0
Balance at End of Year	$ 15,300	$ 15,300	$ 0