Commitments and Contingencies (Details) $ in Thousands	Jun. 30, 2019 USD ($) obligation	Dec. 31, 2018 USD ($)	[1]
Commitments and Contingencies Disclosure [Abstract]
Number of outstanding credit obligations | obligation	14
Letter of credit obligation	$ 48,111
Outstanding construction financings for leased properties	363,160	$ 194,365
Additional financing to complete construction	483,210
Total contingent purchase obligations	$ 8,476

[1] The consolidated balance sheet at December 31, 2018 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements.