EQUITY (Details) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Changes in equity
Balance at the beginning of the period			$ 1,149,478	$ 1,085,675
Comprehensive income:
Net income	55,358	32,628	159,322	90,701
Other comprehensive income (loss)			(12,462)	21,428
Total comprehensive income	1,217	75,251	146,860	112,129
Cash dividends declared - $0.465 per share for 9/30/11 and $0.42 per share for 9/30/10			(39,109)	(35,639)
Cash dividends declared per share (in dollars per share)	$ 0.155	$ 0.14	$ 0.465	$ 0.42
Issuance of shares under benefit plans			15,471	7,426
Purchase of shares for treasury			(27,630)	(22,960)
Balance at the end of the period	1,245,070	1,146,631	1,245,070	1,146,631
Shareholders' Equity
Changes in equity
Balance at the beginning of the period			1,133,497	1,072,346
Comprehensive income:
Net income			159,453	88,741
Other comprehensive income (loss)			(12,692)	21,088
Total comprehensive income			146,761	109,829
Cash dividends declared - $0.465 per share for 9/30/11 and $0.42 per share for 9/30/10			(39,109)	(35,639)
Issuance of shares under benefit plans			15,471	7,426
Purchase of shares for treasury			(27,630)	(22,960)
Balance at the end of the period	1,228,990	1,131,002	1,228,990	1,131,002
Noncontrolling Interests
Changes in equity
Balance at the beginning of the period			15,981	13,329
Comprehensive income:
Net income			(131)	1,960
Other comprehensive income (loss)			230	340
Total comprehensive income			99	2,300
Balance at the end of the period	$ 16,080	$ 15,629	$ 16,080	$ 15,629