Leases (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
As Lessor - Operating Leases
2015	$ 974,684
2016	795,201
2017	627,594
2018	465,224
2019	296,028
Thereafter	219,924
Total	3,378,655
As Lessor - Direct Financing Leases
2015	108,433
2016	94,174
2017	75,385
2018	59,288
2019	41,929
Thereafter	70,101
Total	449,310
As Lessee - Operating Leases
2015	103,624
2016	75,094
2017	51,096
2018	48,589
2019	35,874
Thereafter	65,646
Total	$ 379,923