Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Statement of Income and Comprehensive Income [Abstract]
Net income	$ 19,401	$ 12,985	$ 55,716	$ 25,575
Other comprehensive loss before taxes:
Change in fair value of interest rate swap agreements	(4,239)	(2,202)	(5,902)	(2,183)
Total other comprehensive loss before taxes	(4,239)	(2,202)	(5,902)	(2,183)
Provision for income tax benefit related to components of other comprehensive loss	1,611	837	2,242	830
Other comprehensive loss	(2,628)	(1,365)	(3,660)	(1,353)
Comprehensive income	$ 16,773	$ 11,620	$ 52,056	$ 24,222

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

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+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

- Definition

Total tax effect of the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges that is attributable to the parent entity. The change includes an entity's share of an equity investee's increase (decrease) in deferred hedging gains or losses.

+ References

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This element represents Other Comprehensive Income or Loss, Before Tax, for the period. The pretax revenues, expenses, gains, and losses that under generally accepted accounting principles are included in comprehensive income, but excluded from net income. Includes the entity's proportionate share of an investee's equity adjustments for other comprehensive income. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details

- Definition

This element represents Other Comprehensive Income or Loss, Net of Tax, for the period. Includes deferred gains or losses on qualifying hedges, unrealized holding gains or losses on available-for-sale securities, minimum pension liability, and cumulative translation adjustment. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References

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