Unaudited Condensed Consolidated Statement of Equity Statement - 3 months ended Mar. 31, 2017 - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Capital in Excess of Par Value	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Balance at beginning of period at Dec. 31, 2016	$ 1,095,247	$ 195,403	$ (5,998)	$ 990,203	$ (103,387)	$ 16,492	$ 2,534
Stockholders' Equity [Roll Forward]
Comprehensive income	177,913	0	0	0	174,702	3,164	47
Dividends declared on common stock	(24,433)	0	0	(24,433)	0	0	0
Employee share-based compensation earned	3,633	0	0	3,633	0	0	0
Stock option exercises	15,261	1,122	0	14,139	0	0	0
Restricted stock awards, net of forfeitures	0	209	0	(209)	0	0	0
Purchase of Company common stock	(83,460)	0	(2,813)	(14,701)	(65,946)	0	0
Other	(411)	27	0	(438)	0	0	0
Balance at end of period at Mar. 31, 2017	$ 1,183,750	$ 196,761	$ (8,811)	$ 968,194	$ 5,369	$ 19,656	$ 2,581