Cumulative Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014
Amounts recognized in cumulative other comprehensive income (Loss) by component
Balances at beginning of period	$ (26,724)	$ (38,331)
Other comprehensive income (loss) before reclassifications	4,344	14,729
Amounts reclassified from cumulative other comprehensive (loss) income to net income	1,175	2,397
Net current period other comprehensive income (loss)	5,519	17,126
Balances at end of period	(21,205)	(21,205)
Unrealized Gain (Loss) on Derivative Instruments
Amounts recognized in cumulative other comprehensive income (Loss) by component
Balances at beginning of period	(10,706)	(11,706)
Other comprehensive income (loss) before reclassifications	(632)	(861)
Amounts reclassified from cumulative other comprehensive (loss) income to net income	1,259	2,488
Net current period other comprehensive income (loss)	627	1,627
Balances at end of period	(10,079)	(10,079)
Foreign Currency Translation Adjustments
Amounts recognized in cumulative other comprehensive income (Loss) by component
Balances at beginning of period	(16,060)	(26,647)
Other comprehensive income (loss) before reclassifications	4,961	15,548
Net current period other comprehensive income (loss)	4,961	15,548
Balances at end of period	(11,099)	(11,099)
Equity in Unrealized Gain (Loss) of an Investee
Amounts recognized in cumulative other comprehensive income (Loss) by component
Balances at beginning of period	42	22
Other comprehensive income (loss) before reclassifications	15	42
Amounts reclassified from cumulative other comprehensive (loss) income to net income	(84)	(91)
Net current period other comprehensive income (loss)	(69)	(49)
Balances at end of period	$ (27)	$ (27)