Shareholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period			$ (229,327)
Total other comprehensive income (loss), net of tax	$ 20,409	$ (9,797)	36,118	$ (2,615)
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(193,209)		(193,209)
Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period			(229,327)	(200,607)
OCI before reclassifications			35,133	(1,034)
Amounts reclassified from AOCI			985	(1,581)
Total other comprehensive income (loss), net of tax			36,118	(2,615)
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(193,209)	(203,222)	(193,209)	(203,222)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period			(182,986)	(158,009)
OCI before reclassifications			35,463	3,133
Amounts reclassified from AOCI			0	(1,407)
Total other comprehensive income (loss), net of tax			35,463	1,726
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(147,523)	(156,283)	(147,523)	(156,283)
Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period			43	318
OCI before reclassifications			(330)	(4,080)
Amounts reclassified from AOCI			391	348
Total other comprehensive income (loss), net of tax			61	(3,732)
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	104	(3,414)	104	(3,414)
Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period			(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
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(14,380)	(14,380)	(14,380)	(14,380)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period			(32,004)	(28,536)
OCI before reclassifications			0	(87)
Amounts reclassified from AOCI			594	(522)
Total other comprehensive income (loss), net of tax			594	(609)
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	$ (31,410)	$ (29,145)	$ (31,410)	$ (29,145)