Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income	$ 98,650us-gaap_NetIncomeLoss	$ 86,785us-gaap_NetIncomeLoss	$ 103,034us-gaap_NetIncomeLoss
Other comprehensive income (loss):
Foreign currency translation adjustments	(3,564)	(475)	1,014
Change in fair value of interest rate swap	(1,180)	0	0
Other comprehensive income (loss)	(4,744)	(475)	1,014
Comprehensive income	$ 93,906us-gaap_ComprehensiveIncomeNetOfTax	$ 86,310us-gaap_ComprehensiveIncomeNetOfTax	$ 104,048us-gaap_ComprehensiveIncomeNetOfTax

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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Amount of unrealized gain (loss) related to the increase or decrease in fair value of interest rate derivatives designated as cash flow hedging instruments, which was recorded in accumulated other comprehensive income to the extent that the cash flow hedge was determined to be effective.

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