Broadcast Licenses, Goodwill and Other Intangible Assets (Details 1)	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	12.40%	12.30%	12.20%
Operating profit margin ranges	19.00%	19.50%	19.50%
Market long-term revenue growth rates	1.10%	1.00%	1.30%
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	12.50%	12.40%	12.40%
Operating profit margin ranges	36.40%	36.40%	36.40%
Market long-term revenue growth rates	3.50%	2.90%	3.10%