Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement Of Comprehensive Income [Abstract]
Net income	$ 37,840us-gaap_NetIncomeLoss	$ 12,305us-gaap_NetIncomeLoss
Accumulated losses on derivatives reclassified to derivative interest expense	1,848	1,314
Other Comprehensive Income (Loss), before Tax	1,848	1,314
Income tax effect of items within other comprehensive income	(711)us-gaap_OtherComprehensiveIncomeLossTax	(506)us-gaap_OtherComprehensiveIncomeLossTax
Other comprehensive income, net of income taxes	1,137	808
Total comprehensive income	$ 38,977us-gaap_ComprehensiveIncomeNetOfTax	$ 13,113us-gaap_ComprehensiveIncomeNetOfTax

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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

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Amount before tax, after reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount before tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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