Leases (Summary of Capital Lease and Other Financing Obligations) (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Capital Leased Assets [Line Items]
Capital lease obligations, 2012 (six months remaining)	$ 11,949
Capital lease obligations, 2013	23,957
Capital lease obligations, 2014	24,695
Capital lease obligations, 2015	25,239
Capital lease obligations, 2016	24,413
Capital lease obligations, Thereafter	216,530
Capital lease obligations, Total minimum lease payments	326,783
Capital lease obligations, Plus amount representing residual property value
Capital lease obligations, Less amount representing interest	(131,985)
Capital lease obligations, Present value of net minimum lease payments	194,798
Capital lease obligations, Less current portion	(9,019)
Capital lease obligations, noncurrent portion	185,779
Other financing obligations, 2012 (six months remaining)	10,845
Other financing obligations, 2013	23,816
Other financing obligations, 2014	27,057
Other financing obligations, 2015	29,794
Other financing obligations, 2016	30,906
Other financing obligations, Thereafter	252,588
Other financing obligations, Total minimum lease payments	375,006
Other financing obligations, Plus amount representing residual property value	210,895
Other financing obligations, Less amount representing interest	(303,099)
Other financing obligations, Present value of net minimum lease payments	282,802
Other financing obligations, Less current portion	(3,959)
Other financing obligations, Noncurrent portion	278,843
Total capital lease and other financing obligations, 2012 (six months remaining)	22,794
Total capital lease and other financing obligations, 2013	47,773
Total capital lease and other financing obligations, 2014	51,752
Total capital lease and other financing obligations, 2015	55,033
Total capital lease and other financing obligations, 2016	55,319
Total capital lease and other financing obligations, Thereafter	469,118
Total capital lease and other financing obligations, Total minimum lease payments	701,789
Total capital lease and other financing obligations, Plus amount representing residual property value	210,895
Total capital lease and other financing obligations, Less amount representing interest	(435,084)
Total capital lease and other financing obligations, Present value of net minimum lease payments	477,600
Total capital lease and other financing obligations, Less current portion	(12,978)	(11,542)
Total capital lease and other financing obligations, noncurrent portion	$ 464,622	$ 390,269