CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Common Stock at Par Value [Member]	Capital in Excess of Par Value [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2014	$ 4,158,911	$ 125,424	$ 1,086,082	$ (1,169,673)	$ 4,176,754	$ (64,617)	$ 4,941
Consolidated net income	500,486	0	0	0	497,726	0	2,760
Other comprehensive income (loss)	(218,636)	0	0	0	0	(220,089)	1,453
Amortization of stock-based compensation	47,274	0	47,274	0	0	0	0
Shares issued for stock-based compensation awards	14,900	0	(31,138)	46,038	0	0	0
Tax benefits related to stock-based compensation awards	5,795	0	5,795	0	0	0	0
Repurchases of common stock	(356,434)	0	0	(356,434)	0	0	0
Acquisition of non-controlling interest	47,451	0	0	0	0	0	47,451
Purchase of subsidiary shares from noncontrolling interest	(4,718)	0	(699)	0	0	0	(4,019)
Distributions	(218)	0	0	0	0	0	(218)
Balance at Dec. 31, 2015	4,194,811	125,424	1,107,314	(1,480,069)	4,674,480	(284,706)	52,368
Consolidated net income	524,723	0	0	0	522,750	0	1,973
Other comprehensive income (loss)	(101,105)	0	0	0	0	(99,148)	(1,957)
Amortization of stock-based compensation	39,825	0	39,825	0	0	0	0
Shares issued for stock-based compensation awards	18,967	0	(40,072)	59,039	0	0	0
Tax benefits related to stock-based compensation awards	5,047	0	5,047	0	0	0	0
Repurchases of common stock	(216,446)	0	0	(216,446)	0	0	0
Distributions	(202)	0	0	0	0	0	(202)
Balance at Dec. 31, 2016	4,465,620	125,424	1,112,114	(1,637,476)	5,197,230	(383,854)	52,182
Consolidated net income	407,162	0	0	0	401,962	0	5,200
Other comprehensive income (loss)	263,856	0	0	0	0	258,849	5,007
Amortization of stock-based compensation	39,122	0	39,122	0	0	0	0
Shares issued for stock-based compensation awards	22,195	0	(27,281)	49,476	0	0	0
Repurchases of common stock	(174,239)	0	0	(174,239)	0	0	0
Purchase of subsidiary shares from noncontrolling interest	(23,350)	0	(9,788)	0	0	0	(13,562)
Distributions	(142)	0	0	0	0	0	(142)
Balance at Dec. 31, 2017	$ 5,000,224	$ 125,424	$ 1,114,167	$ (1,762,239)	$ 5,599,192	$ (125,005)	$ 48,685