Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2014
Equity Method Investments [Member]
Accounting Policies [Line Items]
Economic interest in unconsolidated investments in voting rights entities, minimum	20.00%
Economic interest in unconsolidated investments in voting rights entities, maximum	50.00%
Cost Method Investments [Member]
Accounting Policies [Line Items]
Economic interest in unconsolidated investments in voting rights entities, Ownership less than	20.00%