Income Taxes - Narrative (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Significant Accounting Policies [Line Items]  
Unrecognized Tax Benefits 0
Minimum  
Significant Accounting Policies [Line Items]  
Number of Open Tax Years 3 years
Maximum  
Significant Accounting Policies [Line Items]  
Number of Open Tax Years 4 years