Goodwill and Intangible Assets - Summary of the Identifiable Intangible Assets Subject for Amortization (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 17,377	$ 17,337
Impairment Charges	0	0
Accumulated Amortization	16,897	16,381
Net Carrying Amount	480	956
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,860	3,860
Impairment Charges	0	0
Accumulated Amortization	3,822	3,634
Net Carrying Amount	38	226
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,378	10,378
Impairment Charges	0	0
Accumulated Amortization	10,330	10,239
Net Carrying Amount	48	139
Asset Purchase Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,400	1,400
Impairment Charges	0	0
Accumulated Amortization	1,400	1,400
Trade Name and Trademark [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	600	600
Impairment Charges	0	0
Accumulated Amortization	600	586
Net Carrying Amount		14
Capitalized Product Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,139	1,099
Impairment Charges	0	0
Accumulated Amortization	745	522
Net Carrying Amount	$ 394	$ 577