Income Taxes - Major Jurisdictions (Detail)	6 Months Ended
	Jun. 30, 2015
United States [Member]
Income Tax Contingency [Line Items]
Tax Year	2010
New York State [Member]
Income Tax Contingency [Line Items]
Tax Year	2011
New York City [Member]
Income Tax Contingency [Line Items]
Tax Year	2011
United Kingdom [Member]
Income Tax Contingency [Line Items]
Tax Year	2009
Italy [Member]
Income Tax Contingency [Line Items]
Tax Year	2009