Condensed Balance Sheet (Parent Company) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Assets [Abstract]
Cash and cash equivalents	$ 2,976	$ 30,343	$ 22,780	$ 10,703
Total current assets	260,193	209,052
Total assets	2,426,475	1,962,616	1,991,103
Liabilities and Equity [Abstract]
Accounts Payable, Current	25,839	14,196
Other current liabilities	71,916	66,567
Total current liabilities	276,119	225,854
Stockholders' equity:
Common Stock, Value, Issued	473	471
Additional Paid in Capital	274,635	244,211
Accumulated deficit	(117,583)	(82,177)
Accumulated Other Comprehensive Income (Loss), Net of Tax	141	(85)
Stockholders' Equity Attributable to Parent	157,666	162,420
Liabilities and Equity	2,426,475	1,962,616
Parent Company [Member]
Assets [Abstract]
Cash and cash equivalents	2,852	6,200	5,083	9,923
Prepaid expenses and other	120	14
Total current assets	2,972	6,214
Investment in the Partnership	217,425	234,702
Total assets	220,397	240,916
Liabilities and Equity [Abstract]
Other current liabilities	580	501
Total current liabilities	580	501
Deferred Tax Liabilities, Net, Total	62,151	77,995
Stockholders' equity:
Common Stock, Value, Issued	473	471
Additional Paid in Capital	274,635	244,211
Accumulated deficit	(117,583)	(82,177)
Accumulated Other Comprehensive Income (Loss), Net of Tax	141	(85)
Stockholders' Equity Attributable to Parent	157,666	162,420
Liabilities and Equity	$ 220,397	$ 240,916