XML 61 R48.htm IDEA: XBRL DOCUMENT v3.19.2
Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Oct. 05, 2017
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Sep. 30, 2018
Effective income tax rate, percent   18.00% 1.00% 20.00% 268.00%  
Deferred Tax Assets, Net Of Deferred Tax Liabilities   $ 24.3   $ 24.3   $ 30.3
Valuation allowance, deferred tax asset, amount   3.3   3.3   $ 3.4
Unrecognized tax benefits   $ 1.1   $ 1.1    
Majority Shareholder [Member] | D.R. Horton, Inc. [Member]            
Sale of Stock, Percentage of Ownership after Transaction 75.00%