Stock-based compensation expense (Tables)

9 Months Ended

Sep. 30, 2016

Stock-based compensation expense and assumptions

Summary of stock-based compensation expense recognized by income statement classification

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2016		2015		2016		2015
Processing and service costs	$	35,051	$	43,030	$	134,112	$	143,611
Selling, general and administrative expenses		282,408		656,197		1,364,246		1,017,206
Restructuring charges		—		36,924		—		36,924
Total stock-based compensation expense	$	317,459	$	736,151	$	1,498,358	$	1,197,741

Summary of stock-based compensation expense recognized by type

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2016		2015		2016		2015
Stock options	$	217,537	$	528,249	$	766,766	$	783,954
Restricted stock awards		99,922		207,902		731,592		413,787
Total stock-based compensation expense	$	317,459	$	736,151	$	1,498,358	$	1,197,741