Long-Term Debt Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011	Jun. 30, 2010	Jun. 03, 2011	Dec. 31, 2010	Mar. 02, 2010
Long-Term Debt Activity (Textuals) [Abstract]
Debt issue costs		$ 4,521	$ 8,706
Price to repurchase the senior subordinated notes as a percentage of the aggregate principal amount outstanding plus accrued and unpaid interest in case of change of control		101.00%
Price to repurchase the senior subordinated notes as a percentage of the aggregate principal amount outstanding plus accrued and unpaid interest in case of disposition of certain assets		100.00%
Terms related to proceeds from asset dispositions		Notes at 100% of their principal amount, plus accrued and unpaid interest, if any, to the date of repurchase if such proceeds are not otherwise used within 365 days as described in the indenture"
Price to repurchase the senior subordinated notes as a percentage of principal amount plus a make-whole premium in case of redemption at option of company prior to specific date		100.00%
Maximum percentage of principal amount of the senior subordinated notes that can be redeemed prior to specific date		35.00%
Additional percentage of increase in additional interest		0.50%
Terms of registration related to senior subordinated notes		The registration rights agreement provides that the Company will use its commercially reasonable best efforts to have the exchange offer registration statement declared effective by the Commission on or prior to 180 days after the closing of the senior subordinated notes offering, unless the exchange offer would not be permissible by applicable law or Commission policy, the Company will commence the exchange offer and use its commercially reasonable best efforts to issue on the earliest practicable date after the date on which the exchange offer registration statement was declared effective by the Commission, but not later than 30 days thereafter, exchange registered senior subordinated notes in exchange for all senior subordinated notes tendered prior thereto in the exchange offer and if obligated to file the shelf registration statement, the Company will use its commercially reasonable best efforts to file the shelf registration statement with the Commission on or prior to 30 days after such filing obligation arises (and in any event within 210 days after the closing of the senior subordinated notes offering) and to cause the shelf registration statement to be declared effective by the Commission on or prior to 180 days after such obligation arises. If applicable, the Company will use its commercially reasonable best efforts to keep the shelf registration statement effective for a period of two years after the closing of the senior subordinated notes offering, subject to certain exceptions. If the registration statements is not declared effective by the Commission on or prior to the date specified for such effectiveness (the “Effectiveness Target Date”), the Company fails to consummate the exchange offer within 30 business days of the effectiveness target date with respect to the exchange offer registration statement or the shelf registration statement or the exchange offer registration statement is declared effective but thereafter ceases to be effective or usable in connection with resales of notes during the periods specified in the registration rights agreement without being succeeded within two business days by a post-effective amendment to such registration statement that cures such failure and that is itself immediately declared effective (each such event a “Registration Default”), the Company will pay additional interest to each holder of the senior subordinated notes. Such additional interest, with respect to the first 90-day period immediately following the occurrence of any such Registration Default, shall equal an increase in the annual interest rate on the notes by 0.5% per annum"
Maximum amount of additional interest for all Registration Defaults per annum		1.00%
Prepayment Penalties Incurred Upon Early Repayment Of Senior Debt				0
Quarterly term loan payments due on the term loan		2,311
Wrote-off in unamortized debt issue costs related to early retirement of debt	2,183	2,183
Amortization of accumulated other comprehensive loss related to interest rate swap agreement	2,760	2,760
Term loan debt outstanding	910,509	910,509
Borrowing outstanding under revolving credit line	0	0
Carrying value of long-term debt	1,570,604	1,570,604			1,532,441
Fair value of long-term debt	1,629,249	1,629,249			1,581,963
Extended amount outstanding of senior secured credit facility						924,375
Term Loan Of Senior Secured Credit Facility Not Extended						159,225
Maturity date of senior secured credit facility						41548
7.375% Senior Subordinated Notes [Member]
Long-Term Debt Activity (Textuals) [Abstract]
Aggregate principal amount issued				200,000
Interest rate on senior subordinated notes				7.375%
Proceeds from issuance of Senior Subordinated Notes		200,000
Senior subordinated notes, maturity date		Jun. 15, 2021
Prepayment of term loan outstanding under its senior secured credit facility		157,235
Remaining principal amount on the extended amount Due April 30, 2016	866,602	866,602
Extended Term Loan Of Senior Secured Credit Facility [Member]
Long-Term Debt Activity (Textuals) [Abstract]
Carrying value of long-term debt						$ 1,083,600