Business Combinations - Estimated Fair Values of Aggregate Assets and Liabilities Acquired (Detail)	3 Months Ended
	Mar. 31, 2017 USD ($)
Fair Value Of Assets And Liabilities Statement [Line Items]
Payments to Acquire Businesses, Gross	$ 0
Recorded Earn-Out Payable	(211,000)
Other current assets	93,000
Goodwill	429,000
Purchased customer accounts	(32,000)
Total assets acquired	490,000
Other current liabilities	(12,000)
Deferred Tax Liabilities, Net	(689,000)
Total liabilities assumed	(701,000)
Net assets acquired	(211,000)
Maximum Potential Earn- Out Payable	0
Other Acquisitions [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Other current assets	93,000
Goodwill	429,000
Purchased customer accounts	(32,000)
Total assets acquired	490,000
Other current liabilities	(12,000)
Deferred Tax Liabilities, Net	(689,000)
Total liabilities assumed	(701,000)
Net assets acquired	$ (211,000)