Shareholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 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	$ 15,466	$ 8,528	51,584	$ 5,913
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(177,743)		(177,743)
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			49,009	7,895
Amounts reclassified from AOCI			2,575	(1,982)
Total other comprehensive income (loss), net of tax			51,584	5,913
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(177,743)	(194,694)	(177,743)	(194,694)
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			49,304	12,317
Amounts reclassified from AOCI			1,089	(1,407)
Total other comprehensive income (loss), net of tax			50,393	10,910
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(132,593)	(147,099)	(132,593)	(147,099)
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			(295)	(3,709)
Amounts reclassified from AOCI			482	519
Total other comprehensive income (loss), net of tax			187	(3,190)
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	230	(2,872)	230	(2,872)
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	(713)
Amounts reclassified from AOCI			1,004	(1,094)
Total other comprehensive income (loss), net of tax			1,004	(1,807)
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	$ (31,000)	$ (30,343)	$ (31,000)	$ (30,343)