Basis of Presentation - Variable Interest Entity Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets
Net investments in properties	$ 2,594,275	$ 2,704,862
Net investments in direct financing leases	509,483	508,392
In-place lease and tenant relationship intangible assets, net	429,989	438,551
Other assets, net	286,489	228,413
Total assets	4,595,115	4,698,923
Liabilities
Debt, net	1,895,407	2,022,250
Accounts payable, accrued expenses and other liabilities	130,300	128,911
Deferred income taxes	33,625	32,655
Total liabilities	2,272,508	2,383,919
Variable Interest Entity, Primary Beneficiary
Assets
Net investments in properties	183,291	313,000
Net investments in direct financing leases	315,582	315,251
In-place lease and tenant relationship intangible assets, net	18,493	19,336
Other assets, net	54,372	65,557
Total assets	574,618	714,896
Liabilities
Debt, net	201,877	265,874
Accounts payable, accrued expenses and other liabilities	10,154	14,440
Deferred income taxes	16,344	15,687
Total liabilities	$ 229,042	$ 296,673