Other Comprehensive Income and Accumulated Other Comprehensive Income (Changes in AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance			$ 62,301	$ 56,785
Other comprehensive income before reclassifications			(45,864)	77,535
Amounts reclassified from other comprehensive income			(33,054)	(79,892)
Other comprehensive (loss) income, net of tax	$ (17,311)	$ (8,088)	(78,918)	(2,357)
Ending Balance	(16,617)	54,428	(16,617)	54,428
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance			(9,589)	(16,570)
Other comprehensive income before reclassifications			1,003	1,394
Amounts reclassified from other comprehensive income			222	93
Other comprehensive (loss) income, net of tax			1,225	1,487
Ending Balance	(8,364)	(15,083)	(8,364)	(15,083)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance			(785)	(234)
Other comprehensive income before reclassifications			1,893	412
Amounts reclassified from other comprehensive income			(340)	(23)
Other comprehensive (loss) income, net of tax			1,553	389
Ending Balance	768	155	768	155
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance			92,670	87,308
Other comprehensive income before reclassifications			(51,369)	81,794
Amounts reclassified from other comprehensive income			(32,936)	(79,962)
Other comprehensive (loss) income, net of tax			(84,305)	1,832
Ending Balance	8,365	89,140	8,365	89,140
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance			(19,995)	(13,719)
Other comprehensive income before reclassifications			2,609	(6,065)
Amounts reclassified from other comprehensive income			0	0
Other comprehensive (loss) income, net of tax			2,609	(6,065)
Ending Balance	$ (17,386)	$ (19,784)	$ (17,386)	$ (19,784)