Commitments and Contingencies - Amounts of Assets Under Capitalized Lease Agreements and Related Obligations are Included in Debt (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Capital Leased Assets [Line Items]
Accumulated depreciation	$ (2,584)	$ (2,377)
Net assets under capital leases	1,913	1,489
Property and Equipment [Member]
Capital Leased Assets [Line Items]
Other long-term assets	4,367	3,736
Prepaid Expenses and Other Assets [Member]
Capital Leased Assets [Line Items]
Other long-term assets	$ 130	$ 130