Quarterly Financial Data (Unaudited) (Details) (USD $)	0 Months Ended		3 Months Ended									12 Months Ended
	May 20, 2011	Oct. 27, 2010	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011		Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Information Disclosure [Abstract]
Revenue			$ 386,385,000	$ 332,230,000	$ 338,291,000	$ 348,452,000	$ 405,212,000	$ 371,327,000	$ 391,554,000		$ 375,969,000	$ 1,405,358,000	$ 1,544,062,000	$ 1,388,437,000
Gross profit			205,281,000	173,353,000	170,029,000	182,727,000	224,785,000	201,897,000	205,410,000		196,512,000	731,390,000	828,604,000	763,641,000
Earnings from continuing operations			78,177,000	55,949,000	42,405,000	48,825,000	76,835,000	64,390,000	29,822,000	[1]	51,605,000	225,356,000	222,652,000	248,374,000
(Loss) income from discontinued operations			(916,000)	(44,000)	(1,312,000)	(686,000)	(705,000)	329,000	(513,000)		(289,000)	(2,958,000)	(1,178,000)	(248,000)
Net earnings			77,261,000	55,905,000	41,093,000	48,139,000	76,130,000	64,719,000	29,309,000		51,316,000	222,398,000	221,474,000	248,126,000
Basic earnings per share:
Continuing operations			$ 0.53	$ 0.37	$ 0.28	$ 0.32	$ 0.49	$ 0.41	$ 0.19		$ 0.32	$ 1.49	$ 1.41	$ 1.59
Discontinued operations			$ (0.01)	$ 0.00	$ (0.01)	$ 0.00	$ 0.00	$ 0.00	$ 0.00		$ 0.00	$ (0.02)	$ (0.01)	$ 0.00
Basic earnings per share			$ 0.52	$ 0.37	$ 0.27	$ 0.31	$ 0.49	$ 0.41	$ 0.18		$ 0.32	$ 1.47	$ 1.40	$ 1.59
Diluted earnings per share:
Continuing operations			$ 0.52	$ 0.37	$ 0.27	$ 0.31	$ 0.49	$ 0.40	$ 0.18		$ 0.32	$ 1.47	$ 1.38	$ 1.54
Discontinued operations			$ (0.01)	$ 0.00	$ (0.01)	$ 0.00	$ 0.00	$ 0.00	$ 0.00		$ 0.00	$ (0.02)	$ (0.01)	$ 0.00
Diluted earnings per share			$ 0.52	$ 0.37	$ 0.27	$ 0.31	$ 0.48	$ 0.40	$ 0.18		$ 0.32	$ 1.45	$ 1.38	$ 1.54
Litigation settlement payment	$ 39,000,000	$ 3,000,000			$ 39,000,000

[1] Earnings from continuing operations for the second quarter of 2011 include the payment of a $39.0 million litigation settlement. See Note 13 to the Consolidated Financial Statements for additional information.