Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss)
Beginning accumulated other comprehensive (loss) income	$ 6,566	$ (6,212)
Other comprehensive income (loss) before reclassifications	(207)	(629)
Amounts reclassified from accumulated other comprehensive income (loss)	1,241	13,091
Net current-period other comprehensive income (loss)	1,034	12,462
Ending accumulated other comprehensive (loss) income	7,600	6,250
Unrealized Losses on Derivatives
Accumulated Other Comprehensive Income (Loss)
Beginning accumulated other comprehensive (loss) income	(2,029)	(14,268)
Other comprehensive income (loss) before reclassifications	259	(1,100)
Amounts reclassified from accumulated other comprehensive income (loss)	1,948	11,572
Net current-period other comprehensive income (loss)	2,207	10,472
Ending accumulated other comprehensive (loss) income	178	(3,796)
Unrealized Gains on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss)
Beginning accumulated other comprehensive (loss) income	5,295	4,330
Other comprehensive income (loss) before reclassifications	1,613	(235)
Amounts reclassified from accumulated other comprehensive income (loss)	(707)	1,519
Net current-period other comprehensive income (loss)	906	1,284
Ending accumulated other comprehensive (loss) income	6,201	5,614
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss)
Beginning accumulated other comprehensive (loss) income	3,300	3,726
Other comprehensive income (loss) before reclassifications	(2,079)	706
Net current-period other comprehensive income (loss)	(2,079)	706
Ending accumulated other comprehensive (loss) income	$ 1,221	$ 4,432