Minimum Rental Payments Due in Future Period under Operating Leases and Direct Finance Leases which have Non-Cancelable Terms (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Leases User Charges And Commitments [Line Items]
2013	$ 2,344
2014	2,119
2015	2,218
2016	2,233
2017	2,239
Thereafter	41,799
Minimum rental payments, total	52,952
Minimum Rental Payments
Leases User Charges And Commitments [Line Items]
2013	149,673
2014	148,822
2015	146,820
2016	147,887
2017	148,072
Thereafter	1,205,073
Minimum rental payments, total	1,946,347
Minimum Rental Payments | Operating Lease Expense
Leases User Charges And Commitments [Line Items]
2013	119,602
2014	118,150
2015	115,535
2016	115,976
2017	115,523
Thereafter	811,528
Minimum rental payments, total	1,396,314
Minimum Rental Payments | Direct Financing Leases
Leases User Charges And Commitments [Line Items]
2013	30,071
2014	30,672
2015	31,285
2016	31,911
2017	32,549
Thereafter	393,545
Minimum rental payments, total	$ 550,033