Major Customers Data as Percentage of Total Revenues (Detail) (Revenue, Customer Concentration Risk)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Customer A
Revenue, Major Customer [Line Items]
Percentage of total revenues	25.00%		28.00%		24.00%
Customer B
Revenue, Major Customer [Line Items]
Percentage of total revenues		[1]	11.00%		13.00%
Customer C
Revenue, Major Customer [Line Items]
Percentage of total revenues		[1]		[1]	12.00%

[1] *) Less than 10%