Annual report pursuant to Section 13 and 15(d)

Rent Expense under Operating Leases (Detail)

v2.4.1.9
Rent Expense under Operating Leases (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Schedule of Rent Expense [Line Items]      
Rent expense $ 953us-gaap_LeaseAndRentalExpense $ 577us-gaap_LeaseAndRentalExpense $ 301us-gaap_LeaseAndRentalExpense
Less sublease rentals   (47)us-gaap_OperatingLeasesRentExpenseSubleaseRentals1 (35)us-gaap_OperatingLeasesRentExpenseSubleaseRentals1
Total rent expense $ 953us-gaap_OperatingLeasesRentExpenseNet $ 530us-gaap_OperatingLeasesRentExpenseNet $ 266us-gaap_OperatingLeasesRentExpenseNet