Fair Value Measurement - Additional Information (Details) (Significant Unobservable Inputs (Level 3) [Member])
3 Months Ended
Mar. 31, 2015
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]  
Probability of achieving estimated projected earnings or the achievement of certain other objectives 100.00%
Minimum [Member]
 
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]  
Discount rates 1.31%
Maximum [Member]
 
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]  
Discount rates 1.84%