Effect of Correction on the Company's Consolidated Statements of Operations for all Periods (Detail) (USD $) In Thousands, except Per Share data	3 Months Ended							6 Months Ended			9 Months Ended		12 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Sep. 30, 2009	Jun. 30, 2009	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2009	Sep. 30, 2010	Sep. 30, 2009	Dec. 31, 2010	Dec. 31, 2009
Interest expense, net of interest capitalized	$ (92,968)	$ (100,625)	$ (89,082)	$ (90,661)	$ (91,528)	$ (74,596)	$ (69,517)	$ (193,593)	$ (182,189)	$ (148,979)	$ (271,271)	$ (223,574)	$ (371,207)	$ (309,948)
Total other expense	(74,699)	(71,124)	(95,323)	(89,953)	(11,909)	(77,133)	(91,338)	(145,823)	(101,862)	(171,829)	(197,185)	(248,961)	(286,980)	(336,026)
Net Income (Loss)	93,491	78,410	350,179	53,731	79,843	229,708	(36,276)	171,901	133,574	(72,514)	483,753	157,195	515,653	152,485
Earning (Loss) per Share:
Basic	$ 0.43	$ 0.36	$ 1.63	$ 0.25	$ 0.37	$ 1.07	$ (0.17)	$ 0.79	$ 0.62	$ (0.34)	$ 2.25	$ 0.74	$ 2.40	$ 0.71
Diluted	$ 0.43	$ 0.36	$ 1.61	$ 0.25	$ 0.37	$ 1.07	$ (0.17)	$ 0.78	$ 0.61	$ (0.34)	$ 2.23	$ 0.73	$ 2.37	$ 0.71
As Previously Reported
Interest expense, net of interest capitalized		(87,483)	(82,494)	(83,846)	(83,924)	(73,912)	(68,327)		(167,770)	(147,789)	(250,264)	(221,701)	(339,393)	(300,012)
Total other expense		(57,982)	(88,735)	(83,138)	(4,305)	(76,449)	(90,148)		(87,443)	(170,639)	(176,178)	(247,088)	(255,166)	(326,090)
Net Income (Loss)		91,552	356,767	60,546	87,447	230,392	(35,086)		147,993	(71,324)	504,760	159,068	547,467	162,421
Earning (Loss) per Share:
Basic		$ 0.42	$ 1.66	$ 0.28	$ 0.41	$ 1.08	$ (0.16)		$ 0.69	$ (0.33)	$ 2.35	$ 0.74	$ 2.55	$ 0.76
Diluted		$ 0.42	$ 1.64	$ 0.28	$ 0.40	$ 1.07	$ (0.16)		$ 0.68	$ (0.33)	$ 2.32	$ 0.74	$ 2.51	$ 0.75
Adjustment
Interest expense, net of interest capitalized		(13,142)	(6,588)	(6,815)	(7,604)	(684)	(1,190)		(14,419)	(1,190)	(21,007)	(1,873)	(31,814)	(9,936)
Total other expense		(13,142)	(6,588)	(6,815)	(7,604)	(684)	(1,190)		(14,419)	(1,190)	(21,007)	(1,873)	(31,814)	(9,936)
Net Income (Loss)		$ (13,142)	$ (6,588)	$ (6,815)	$ (7,604)	$ (684)	$ (1,190)		$ (14,419)	$ (1,190)	$ (21,007)	$ (1,873)	$ (31,814)	$ (9,936)
Earning (Loss) per Share:
Basic		$ (0.06)	$ (0.03)	$ (0.03)	$ (0.04)	$ 0.00	$ (0.01)		$ (0.07)	$ (0.01)	$ (0.10)	$ (0.01)	$ (0.15)	$ (0.05)
Diluted		$ (0.06)	$ (0.03)	$ (0.03)	$ (0.04)	$ 0.00	$ (0.01)		$ (0.07)	$ (0.01)	$ (0.10)	$ (0.01)	$ (0.15)	$ (0.05)