Acquisitions (Second Quarter 2016) - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016 Client
Savitz Organization [Member]
Business Acquisition, Contingent Consideration [Line Items]
Effective date of acquisition	Apr. 01, 2016
Acquired entity, name	Savitz Organization
Flex-Pay Business Services Inc [Member]
Business Acquisition, Contingent Consideration [Line Items]
Effective date of acquisition	Jun. 01, 2016
Acquired entity, name	Flex-Pay Business Services, Inc
Flex-Pay Business Services Inc [Member] | Minimum [Member]
Business Acquisition, Contingent Consideration [Line Items]
Number of employees covered	3,600