Credit Facility - Additional Information (Detail) - USD ($)		12 Months Ended
	Dec. 23, 2014	Dec. 31, 2016	Feb. 22, 2017	Dec. 31, 2015
Line of Credit Facility [Line Items]
Line of credit maximum borrowing percentage of accounts receivable		85.00%
Line of credit maximum borrowing percentage of employee placement accounts		80.00%
Line of credit maximum borrowings percentage of corporate headquarters		80.00%
Quarterly reduction of additional corporate headquarters borrowing base		1.25%
Line of credit basis spread on variable rate under condition one		1.25%
Line of credit facility basis spread on variable rate under condition two		0.50%
Line of credit basis spread on variable rate under condition three		0.125%
Percentage of commitment of all lenders as condition to maintain min fixed charge coverage ratio		10.00%
Amount of commitment of all lenders as condition to maintain min fixed charge coverage ratio		$ 11,000,000
Line of credit remaining borrowing capacity		41,400,000
Long-term debt - credit facility		$ 111,500,000		$ 80,500,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit maximum borrowing capacity	$ 170,000,000
Line of credit current borrowing capacity available from amendment	50,000,000
Line of credit unused capacity commitment fee percentage threshold		35.00%
Line of credit limit on equity security repurchases, max percent availability of borrowing capacity		15.00%
Line of credit limit on equity security repurchases, availability of borrowing capacity		$ 15,000,000
Line of credit covenant limit on distributions max percent availability of borrowing capacity		12.50%
Line of credit covenant limit on distributions availability of borrowing capacity		$ 20,600,000
Revolving Credit Facility | Subsequent Event
Line of Credit Facility [Line Items]
Line of credit remaining borrowing capacity			$ 35,700,000
Long-term debt - credit facility			$ 117,200,000
Revolving Credit Facility | Below Threshold
Line of Credit Facility [Line Items]
Line of credit unused capacity commitment fee percentage		0.35%
Revolving Credit Facility | Above Threshold
Line of Credit Facility [Line Items]
Line of credit unused capacity commitment fee percentage		0.25%
Letter of Credit
Line of Credit Facility [Line Items]
Line of credit sub-limit for letters of credit	$ 15,000,000