Commitments and Contingencies - Schedule of Unconditional Purchase Obligations (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Unconditional purchase obligations, rolling maturity  
2015 $ 55,828
2016 28,520
2017 26,973
2018 26,163
2019 26,163
Thereafter 95,258
Total $ 258,905