Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Condensed Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net earnings	$ 171,280	$ 157,361	$ 327,053	$ 304,587
Other comprehensive income/(loss), net of tax:
Foreign currency translation adjustments	37,212	19,803	(54,798)	6,992
Post retirement benefit plan adjustment	0	0	1,063	0
Total other comprehensive income/(loss), net of tax	37,212	19,803	(55,861)	6,992
Comprehensive income	$ 208,492	$ 177,164	$ 271,192	$ 311,579