Customer Concentration (Tables)

12 Months Ended

Dec. 31, 2018

Significant Contractual Relationship [Abstract]

Schedules of Concentration of Risk, by Risk Factor

Accounts receivable from significant clients, those representing 10% or more of total accounts receivable for the dates noted, are summarized below:

	December 31,
($ in thousands)	2018	2017
Sprint	$43,227	$43,405
% of total accounts receivable	79%	80%

Correspondingly, revenue from significant clients, those representing 10% or more of total revenue for the respective periods, is summarized as follows:

	Year Ended December 31,
	2018	2017	2016
Sprint	68%	72%	69%