Financing Arrangements - Consolidated Debt (Details 2) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Nov. 30, 2014	Dec. 31, 2013	Sep. 30, 2011	Feb. 29, 2004
Current:
Current debt		$ 28,742
Long-Term:
Long-Term debt	$ 992,664	991,685
1.5% Convertible Senior Notes due February 15, 2024
Current:
Current debt		$ 18,324
Interest rates on debt
Interest rate (as a percent)		1.50%		1.50%		1.50%
3.375% Senior Notes
Long-Term:
Long-Term debt	$ 497,486	$ 497,045
Interest rates on debt
Interest rate (as a percent)	3.375%	3.375%			3.375%
3.5% Senior Notes
Long-Term:
Long-Term debt	$ 495,178	$ 494,640
Interest rates on debt
Interest rate (as a percent)	3.50%	3.50%	3.50%
Other borrowings
Current:
Current debt		$ 10,418