Segment and Geographic Information (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment trading revenues									$ 37,419	$ 16,418	$ 0
Operating and Capital Leases Income Statement Lease Revenue	$ 313,856	$ 302,120	$ 281,939	$ 265,602	$ 259,547	$ 247,789	$ 158,333	$ 163,025	1,163,517	828,694	707,839
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment trading revenues									17,342	7,410
Operating and Capital Leases Income Statement Lease Revenue									491,996	397,500	403,910
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment trading revenues									8,383	4,439
Operating and Capital Leases Income Statement Lease Revenue									518,598	334,118	226,905
BERMUDA
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment trading revenues									22	0
Operating and Capital Leases Income Statement Lease Revenue									1,745	464	120
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment trading revenues									7,747	3,082
Operating and Capital Leases Income Statement Lease Revenue									111,558	58,945	41,566
Other international
Revenues from External Customers and Long-Lived Assets [Line Items]
Equipment trading revenues									3,925	1,487
Operating and Capital Leases Income Statement Lease Revenue									$ 39,620	$ 37,667	$ 35,338