Shareholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized loss on hedging instruments at January 1,	$ (196,305)
Total other comprehensive income (loss), net of tax	(1,780)	$ 17,883
Net unrealized loss on hedging instruments at March 31,	(198,085)
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	(1,848)	17,483
Amounts reclassified from AOCI	68	400
Total other comprehensive income (loss), net of tax	(1,780)	17,883
Net unrealized loss on hedging instruments at March 31,	(198,085)	(152,595)
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	(2,386)	16,300
Amounts reclassified from AOCI	0	0
Total other comprehensive income (loss), net of tax	(2,386)	16,300
Net unrealized loss on hedging instruments at March 31,	(159,875)	(112,348)
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	211	1,183
Amounts reclassified from AOCI	(76)	(14)
Total other comprehensive income (loss), net of tax	135	1,169
Net unrealized loss on hedging instruments at March 31,	1,336	2,135
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 March 31,	(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	327	0
Amounts reclassified from AOCI	144	414
Total other comprehensive income (loss), net of tax	471	414
Net unrealized loss on hedging instruments at March 31,	$ (25,166)	$ (28,002)