Geographic Information (Revenue by Geographic Locations) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) Reportable_Segments	Sep. 30, 2018 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Reportable_Segments			1
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,224,850	$ 1,183,567	$ 1,224,850	$ 1,183,567
Operating revenue	147,233	128,643	434,432	361,499
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	394,870	390,551	394,870	390,551
Operating revenue	45,038	48,395	136,181	146,697
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	6,890	5,846	6,890	5,846
Operating revenue	1,207	1,267	3,516	4,323
Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	15,637	16,348	15,637	16,348
Operating revenue	5,400	4,586	14,397	15,141
Australia
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,850	1,485	1,850	1,485
Operating revenue	8,643	8,576	25,997	26,803
Singapore
Revenues from External Customers and Long-Lived Assets [Line Items]
Pre-Existing Revenue	2,300
Long-lived assets	18,262	17,805	18,262	17,805
Operating revenue	1,260	1,731	5,404	5,871
New Zealand
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	594	158	594	158
Operating revenue	494	454	1,504	1,467
India
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	705,255	672,699	705,255	672,699
Operating revenue	77,145	56,631	223,962	139,985
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	22,384	23,880	22,384	23,880
Operating revenue	3,584	3,854	11,005	11,726
INDONESIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	118	98	118	98
Operating revenue	2,004	1,683	7,177	5,052
PHILIPPINES
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	606	448	606	448
Operating revenue	2,185	1,147	4,682	3,740
UNITED ARAB EMIRATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	58,384	54,249	58,384	54,249
Operating revenue	273	$ 319	$ 607	$ 694
Indian Led [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenue	$ 156,700