Income Taxes - Earliest Tax Years Subject to Examination by Major Jurisdiction (Detail)	3 Months Ended
	Mar. 31, 2017
U.S. Federal [Member]
Income Tax Examination [Line Items]
Open tax years by major tax jurisdiction	2011
New York State and City [Member]
Income Tax Examination [Line Items]
Open tax years by major tax jurisdiction	2007
United Kingdom [Member] | Foreign Tax Authority [Member]
Income Tax Examination [Line Items]
Open tax years by major tax jurisdiction	2014
Japan [Member] | Foreign Tax Authority [Member]
Income Tax Examination [Line Items]
Open tax years by major tax jurisdiction	2014
Hong Kong [Member] | Foreign Tax Authority [Member]
Income Tax Examination [Line Items]
Open tax years by major tax jurisdiction	2010