Shareholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized loss on hedging instruments at January 1,			$ (196,305)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	$ (2,421)	$ (2,409)	(2,497)	$ (2,423)
Total other comprehensive income (loss), net of tax	3,736	(33,273)	1,956	(15,390)
Net unrealized loss on hedging instruments at June 30,	(194,349)		(194,349)
Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized loss on hedging instruments at January 1,			(196,305)	(170,478)
OCI before reclassifications			4,462	(13,782)
Amounts reclassified from AOCI			(2,506)	(1,608)
Total other comprehensive income (loss), net of tax			1,956	(15,390)
Net unrealized loss on hedging instruments at June 30,	(194,349)	(185,868)	(194,349)	(185,868)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized loss on hedging instruments at January 1,			(157,489)	(128,648)
OCI before reclassifications			2,801	(17,860)
Amounts reclassified from AOCI			0	0
Total other comprehensive income (loss), net of tax			2,801	(17,860)
Net unrealized loss on hedging instruments at June 30,	(154,688)	(146,508)	(154,688)	(146,508)
Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized loss on hedging instruments at January 1,			1,201	966
OCI before reclassifications			998	4,078
Amounts reclassified from AOCI				(2,423)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax			(2,497)
Total other comprehensive income (loss), net of tax			(1,499)	1,655
Net unrealized loss on hedging instruments at June 30,	(298)	2,621	(298)	2,621
Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized loss on hedging instruments at January 1,			(14,380)	(14,380)
OCI before reclassifications			0	0
Amounts reclassified from AOCI			0	0
Total other comprehensive income (loss), net of tax			0	0
Net unrealized loss on hedging instruments at June 30,	(14,380)	(14,380)	(14,380)	(14,380)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized loss on hedging instruments at January 1,			(25,637)	(28,416)
OCI before reclassifications			663	0
Amounts reclassified from AOCI			(9)	815
Total other comprehensive income (loss), net of tax			654	815
Net unrealized loss on hedging instruments at June 30,	$ (24,983)	$ (27,601)	$ (24,983)	$ (27,601)