CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Issuance of shares of common stock for acquisition of PAY.ON		227,917
Repurchase of common stock, shares	3,020,926		3,578,427
PAY.ON RSAs [Member]
Issuance of shares under stock plan portion of PAY.ON acquisition agreement		476,750