Acquisitions - Summary of Purchase Price Allocation for Company's Acquisition of LER (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
Goodwill	$ 36,647,000	$ 36,647,000
LER [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	500,000
Trade accounts receivable	2,100,000
Prepaids and other assets	100,000
Property and equipment	100,000
Intangible assets subject to amortization	500,000
Goodwill	700,000
Current liabilities	(1,800,000)
Total	$ 2,200,000