Held for Sale (Assets and Liabilities of Properties Held for Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets Held for Sale [Abstract]
Real estate	$ 130,380	$ 293,003
Property and equipment, net	2,003	3,116
Total assets	761,912	733,208
Liabilities Held for Sale [Abstract]
Accounts payable	2,382	4,804
Other liabilities	13,934	19,702
Total Liabiltiies	156,280	171,090
Disposal Group, Held-for-sale, Not Discontinued Operations
Assets Held for Sale [Abstract]
Real estate	180,247	19,931
Timber	0	1,682
Other intangible assets	0	1,681
Oil and gas properties and equipment, net	0	782
Property and equipment, net	1,360	6,301
Total assets	181,607	30,377
Liabilities Held for Sale [Abstract]
Accounts payable	1,017	0
Other liabilities	0	103
Total Liabiltiies	$ 1,017	$ 103