Share Based Compensation Summary of Stock Option Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Shares
Outstanding, September 30, 2016 | shares	0
Converted on October 1, 2016 | shares	500,000
Granted | shares	0
Exercised | shares	0
Forfeited | shares	0
September 30, 2017 | shares	500,000
Weighted Average Exercise Price
Outstanding, September 30, 2016 | $ / shares	$ 0.00
Converted on October 1, 2016 | $ / shares	18.37
Granted | $ / shares	0.00
Exercised | $ / shares	0.00
Forfeited | $ / shares	0.00
September 30, 2017 | $ / shares	$ 18.55
Weighted average remaining contractual terms, options outstanding	5 years 7 months
Aggregate intrinsic value, options outstanding | $	$ 9.6
Weighted average remaining contractual terms, options exercisable	5 years 7 months
Aggregate intrinsic value, options exercisable | $	$ 9.3