Business Segment Information - People's Republic of China Including Hong Kong Percentage Share of the Company's Total Revenue, Net Revenue, Total Identifiable Assets or Equity (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Total revenues | People's Republic of China, including Hong Kong
Concentration Risk [Line Items]
Concentration percentage	32.00%	33.00%	33.00%
Net revenues | People's Republic of China, including Hong Kong
Concentration Risk [Line Items]
Concentration percentage	19.00%	16.00%	16.00%
Identifiable assets at year end | People's Republic of China, including Hong Kong
Concentration Risk [Line Items]
Concentration percentage	13.00%	14.00%	14.00%
Equity | People's Republic of China, including Hong Kong
Concentration Risk [Line Items]
Concentration percentage	10.00%	9.00%	11.00%
Lower end | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration percentage	10.00%	10.00%	10.00%