Fair Value Measurements - Quantitative Information About Level 3 Fair Value Measurements (Detail) (Significant Unobservable Inputs (Level 3) [Member], Indicative Bids [Member], USD $)	12 Months Ended
	Dec. 31, 2013
Equity Method Investments [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets measured at fair value	$ 6,551,000
Valuation Technique	Indicative Bids
Input range
Equity Method Investments One [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets measured at fair value	150,000
Valuation Technique	Indicative Bids
Input range
Equity Method Investments Two [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets measured at fair value	$ 50,000
Valuation Technique	Indicative Bids
Input range
Weighted Average [Member] | Equity Method Investments [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Input range
Weighted Average [Member] | Equity Method Investments One [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Input range
Weighted Average [Member] | Equity Method Investments Two [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Input range