Share-based Compensation - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation		$ 14,395	$ 21,430	$ 19,454
Share-based compensation expense, change from prior period	$ (1,500)	7,000	2,000
Cost Of ATM Operating Revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation		543	875	1,218
Selling, General and Administrative Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation		$ 13,852	$ 20,555	$ 18,236