Leased Properties - Operating Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease assets	$ 1,075,969	$ 0
Current operating lease liabilities	270,731
Noncurrent operating lease liabilities	825,567	$ 0
Total operating lease liabilities	$ 1,096,298