Weighted-Average Assumptions Used to Determine Net Periodic Benefit Cost (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule of Net Periodic Benefit Costs Weighted Average Assumptions [Line Items]
Discount rate per annum	8.50%	8.65%
Discount rate for Years ended Dec 31, 2015 and 2014	8.5% per annum for 2015 and 8.65% per annum for 2014
Long-term rate of compensation increase for Years ended Dec 31, 2015 and 2014	11% per annum for first year, 10% for next five years & 7% thereafter
First Year [Member]
Schedule of Net Periodic Benefit Costs Weighted Average Assumptions [Line Items]
Long-term rate of compensation increase per annum	11.00%	11.00%
Next Five Years
Schedule of Net Periodic Benefit Costs Weighted Average Assumptions [Line Items]
Long-term rate of compensation increase per annum	10.00%	10.00%
There After [Member]
Schedule of Net Periodic Benefit Costs Weighted Average Assumptions [Line Items]
Long-term rate of compensation increase per annum	7.00%	7.00%