Business and Credit Concentrations (Narrative) (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2017
Accounts Receivable [Member] | Customer Concentration Risk One [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage			15.00%		24.00%
Accounts Receivable [Member] | Customer Concentration Risk Two [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage			14.00%		10.00%
Sales Revenue, Net [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage		13.00%		14.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Minimum [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	10.00%	10.00%	10.00%	10.00%