Comprehensive Income (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Amounts included in AOCL
Balance, Beginning	$ (3,480)
Amounts reclassified into earnings	8	654
Changes in fair value	290	2,923
Balance, Ending	(3,182)
Interest Rate Swap [Member]
Amounts included in AOCL
Balance, Beginning	(5,652)
Amounts reclassified into earnings	708	1,157
Changes in fair value	(623)	41
Balance, Ending	(5,567)
Fuel Hedges [Member]
Amounts included in AOCL
Balance, Beginning	2,172
Amounts reclassified into earnings	(700)	(503)
Changes in fair value	913	2,882
Balance, Ending	$ 2,385

Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

+ References+ Details

Net of tax effect of the reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period.

+ References

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+ Details

- Definition

Change in accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges, net of tax effect. The after tax effect change includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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