Condensed Consolidating Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
ASSETS
Cash and cash equivalents	$ 62,897	$ 55,802
Accounts receivable, net of allowance	252,764	269,685
Deferred tax assets	8,022	11,768
Prepaid expenses and other current assets	27,059	18,676
Total current assets	350,742	359,429
Property and equipment, net	2,568,791	2,608,740
Restricted cash	5,022	5,013
Investment in direct financing lease	7,467	9,233
Goodwill	11,988	11,988
Other assets	30,732	25,047
Total assets	2,974,742	3,019,631
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	166,000	195,726
Income taxes payable	102	605
Current liabilities of discontinued operations	356	2,031
Total current liabilities	166,458	198,362
Long-term debt	1,111,545	1,245,014
Deferred tax liabilities	139,526	136,503
Other liabilities	35,593	31,730
Total liabilities	1,453,122	1,611,609
Total stockholders' equity	1,521,620	1,408,022	1,470,871	1,442,546
Total liabilities and stockholders' equity	2,974,742	3,019,631
Parent
ASSETS
Accounts receivable, net of allowance	136,128
Deferred tax assets	137
Prepaid expenses and other current assets	1,766
Total current assets	138,031
Property and equipment, net	2,462,917
Investment in direct financing lease	7,467
Other assets	191,502
Total assets	2,799,917
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	28,061
Total current liabilities	28,061
Long-term debt	1,111,545
Deferred tax liabilities	138,691
Total liabilities	1,278,297
Total stockholders' equity	1,521,620
Total liabilities and stockholders' equity	2,799,917
Combined Subsidiary Guarantors
ASSETS
Cash and cash equivalents	62,897
Accounts receivable, net of allowance	255,192
Deferred tax assets	7,885
Prepaid expenses and other current assets	35,175
Total current assets	361,149
Property and equipment, net	105,874
Restricted cash	5,022
Goodwill	11,988
Other assets	114,953
Total assets	598,986
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	286,342
Income taxes payable	102
Current liabilities of discontinued operations	356
Total current liabilities	286,800
Long-term debt	100,000
Deferred tax liabilities	835
Other liabilities	35,593
Total liabilities	423,228
Total stockholders' equity	175,758
Total liabilities and stockholders' equity	598,986
Consolidating Adjustments
ASSETS
Accounts receivable, net of allowance	(138,556)
Prepaid expenses and other current assets	(9,882)
Total current assets	(148,438)
Other assets	(275,723)
Total assets	(424,161)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	(148,403)
Total current liabilities	(148,403)
Long-term debt	(100,000)
Total liabilities	(248,403)
Total stockholders' equity	(175,758)
Total liabilities and stockholders' equity	$ (424,161)