CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Class A ordinary shares/ Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Treasury shares [Member]	Accumulated other comprehensive income (loss) [Member]
Balance at Dec. 31, 2011	$ 4,325,987	$ 15,947	$ 1,478,233	$ 3,186,362	$ (128,884)	$ (225,671)
Balance (in shares) at Dec. 31, 2011		123,581
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net shares issued (acquired) under share-based compensation plans	(3,456)	64	(21,428)	0	17,908	0
Net shares issued (acquired) under share-based compensation plans (in shares)		552
Share-based compensation	10,874	0	10,874	0	0	0
Excess tax benefit from share-based compensation plans	1,142	0	1,142	0	0	0
Retirement benefit adjustments, net of taxes	6,777	0	0	0	0	6,777
Cancelation of treasury shares	0	(419)	(109,068)		109,487
Other	0
Other (in shares)	52	52
Net income	98,952	0	0	98,952	0	0
Balance at Jun. 30, 2012	4,440,276	15,592	1,359,753	3,285,314	(1,489)	(218,894)
Balance (in shares) at Jun. 30, 2012		124,185
Balance at Dec. 31, 2012	4,531,724	15,593	1,372,135	3,366,964	(1,886)	(221,082)
Balance (in shares) at Dec. 31, 2012		124,211
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net shares issued (acquired) under share-based compensation plans	(1,836)	4	2,107	0	(3,947)	0
Net shares issued (acquired) under share-based compensation plans (in shares)		1
Share-based compensation	13,379	0	13,379	0	0	0
Excess tax benefit from share-based compensation plans	157	0	157	0	0	0
Retirement benefit adjustments, net of taxes	7,285	0	0	0	0	7,285
Other	1,820		1,820
Net income	150,978	0	0	150,978	0	0
Balance at Jun. 30, 2013	$ 4,703,507	$ 15,597	$ 1,389,598	$ 3,517,942	$ (5,833)	$ (213,797)
Balance (in shares) at Jun. 30, 2013		124,212