Stock-based compensation expense (Tables)

3 Months Ended

Mar. 31, 2016

Stock-based compensation expense and assumptions

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

	Three Months Ended
	March 31,
	2016		2015
Processing and service costs	$	48,806	$	50,497
Selling, general and administrative expenses		555,162		182,965
Total stock-based compensation expense	$	603,968	$	233,462

Summary of stock-based compensation expense recognized by type

	Three Months Ended
	March 31,
	2016		2015
Stock options	$	281,396	$	131,272
Restricted stock awards		322,572		102,190
Total stock-based compensation expense	$	603,968	$	233,462