Geographic Information (Revenue by Geographic Locations) (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) Reportable_Segments	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Reportable_Segments			1
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net, Increase (Decrease)	$ 35,843,000		$ 102,209,000
Long-lived assets	1,080,203,000	$ 785,158,000	1,080,203,000	$ 785,158,000	$ 1,080,203,000
Operating revenue	128,643,000	92,800,000	361,499,000	259,290,000
Increase (Decrease) in Deferred Income Taxes			3,077,000	6,327,000
Goodwill, Acquired During Period			261,428,000			$ 233,095,000
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net, Increase (Decrease)			(11,000,000)
Long-lived assets	393,066,000	390,950,000	393,066,000	390,950,000	393,066,000
Operating revenue	48,395,000	52,603,000	146,697,000	157,682,000
Long Lived Assets, Increase (Decrease)					2,100,000
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net, Increase (Decrease)			(1,600,000)
Long-lived assets	6,265,000	6,674,000	6,265,000	6,674,000	6,265,000
Operating revenue	1,267,000	1,827,000	4,323,000	5,969,000
Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	18,338,000	23,919,000	18,338,000	23,919,000	18,338,000
Operating revenue	4,586,000	6,268,000	15,141,000	14,486,000
Long Lived Assets, Increase (Decrease)					$ (5,600,000)
Foreign Currency Translation Gain (Loss), Percent					(22.00%)
Foreign Currency Translation Related To Long Lived Assets					$ (5,200,000)
Australia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net, Increase (Decrease)			1,700,000
Long-lived assets	1,605,000	1,273,000	1,605,000	1,273,000	1,605,000
Operating revenue	8,576,000	8,575,000	26,803,000	25,091,000
Effect of Exchange Rate on Revenue			(300,000)
Singapore
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	19,054,000	17,427,000	19,054,000	17,427,000	19,054,000
Operating revenue	1,731,000	1,368,000	5,871,000	4,493,000
New Zealand
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	267,000	251,000	267,000	251,000	267,000
Operating revenue	454,000	462,000	1,467,000	1,485,000
India
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net, Increase (Decrease)			102,500,000
Long-lived assets	561,966,000	268,449,000	561,966,000	268,449,000	561,966,000
Operating revenue	56,631,000	17,509,000	139,985,000	37,508,000
Long Lived Assets, Increase (Decrease)					293,500,000
Increase In Value Of Long Lived Assets From Business Acquisitions					319,500,000
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	24,852,000	22,613,000	24,852,000	22,613,000	24,852,000
Operating revenue	3,854,000	4,188,000	11,726,000	12,576,000
Long Lived Assets, Increase (Decrease)					(2,200,000)
Dubai [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	54,252,000	53,602,000	54,252,000	53,602,000	54,252,000
Operating revenue	319,000	0	694,000	0
INDONESIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	64,000	0	64,000	0	64,000
Operating revenue	1,683,000	0	5,052,000	0
PHILIPPINES
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	474,000	0	474,000	0	$ 474,000
Operating revenue	$ 1,147,000	$ 0	3,740,000	$ 0
ItzCash, Youfirst, WallStreet, PML, Via, and Transcorp [Member] | India
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net, Increase (Decrease)			103,800,000
e- governance contracts [Member] | India
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net, Increase (Decrease)			$ (900,000)