Income Taxes - Schedule of Difference Between US Federal Statutory Income Tax Rate and Effective Income Tax Rate (Details)	3 Months Ended	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2018
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	24.50%	24.50%
State income taxes, net of federal tax benefit	3.00%	3.10%
Effect of foreign operations	1.00%	0.90%
Deferred tax revaluation		(19.60%)
Deemed repatriation tax		6.70%
Other, net		0.30%
Effective tax rate	28.50%	15.90%