Commitments and Contingencies (Details) (USD $)	Dec. 31, 2014
Future minimum lease payments due under operating and capital leases
Operating Leases 2014	$ 15,078,000
Capital Leases 2014	13,157,000	[1]
Operating Leases 2015	15,158,000
Capital Leases 2015	4,732,000	[1]
Operating Leases 2016	15,212,000
Capital Leases 2016	4,732,000	[1]
Operating Leases 2017	15,249,000
Capital Leases 2017	4,679,000	[1]
Operating Leases 2018	15,208,000
Capital Leases 2018	4,333,000	[1]
Operating Leases Thereafter	840,499,000
Capital Leases Thereafter	80,093,000	[1]
Operating Lease Total	916,404,000
Capital Leases Total	$ 111,726,000	[1]

[1] Amounts above represent principal and interest obligations under capital lease arrangements. Related assets with a gross value of $185,244,000 and accumulated depreciation of $13,132,000 are recorded in real property.