Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Plant and equipment
Property and equipment, net	$ 2,682,661		$ 2,669,732
Increase in property and equipment	12,900
Depreciation expense	63,400	$ 64,800
Interest capitalized in connection with major construction projects	600	100
Master Lease Agreement
Plant and equipment
Depreciation expense	23,200	$ 22,300
Land And Land Improvements Owned
Plant and equipment
Property and equipment	43,211		42,350
Land and Land Improvements Leased
Plant and equipment
Property and equipment	382,702		382,702
Building and Building improvements Owned
Plant and equipment
Property and equipment	187,696		173,043
Buildings and Building Improvements Leased
Plant and equipment
Property and equipment	2,219,018		2,219,018
Furniture, Fixtures and Equipment
Plant and equipment
Property and equipment	1,218,830		1,213,143
Leasehold Improvements
Plant and equipment
Property and equipment	120,209		120,984
Construction in Progress
Plant and equipment
Property and equipment	115,955		69,367
Non-leased Assets
Plant and equipment
Property and equipment	1,685,901		1,618,887
Less accumulated depreciation	(1,019,401)		(988,490)
Property and equipment, net	666,500		630,397
Leased Assets
Plant and equipment
Property and equipment	2,601,720		2,601,720
Less accumulated depreciation	(585,559)		(562,385)
Property and equipment, net	$ 2,016,161		$ 2,039,335