Annual report pursuant to Section 13 and 15(d)

Basis of Presentation - Effects of Prior Period Errors in Consolidated Statement of Cash Flows (Detail)

v2.4.0.8
Basis of Presentation - Effects of Prior Period Errors in Consolidated Statement of Cash Flows (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended
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
Dec. 31, 2012
As Previously Reported [Member]
Sep. 30, 2012
As Previously Reported [Member]
Jun. 30, 2012
As Previously Reported [Member]
Mar. 31, 2012
As Previously Reported [Member]
Dec. 30, 2011
As Previously Reported [Member]
Sep. 30, 2011
As Previously Reported [Member]
Jun. 30, 2011
As Previously Reported [Member]
Mar. 31, 2011
As Previously Reported [Member]
Dec. 31, 2012
As Previously Reported [Member]
Dec. 31, 2011
As Previously Reported [Member]
Dec. 31, 2010
As Previously Reported [Member]
Dec. 31, 2012
As Adjusted [Member]
Sep. 30, 2012
As Adjusted [Member]
Jun. 30, 2012
As Adjusted [Member]
Mar. 31, 2012
As Adjusted [Member]
Dec. 31, 2011
As Adjusted [Member]
Sep. 30, 2011
As Adjusted [Member]
Jun. 30, 2011
As Adjusted [Member]
Mar. 31, 2011
As Adjusted [Member]
Dec. 31, 2012
As Adjusted [Member]
Dec. 31, 2011
As Adjusted [Member]
Dec. 31, 2010
As Adjusted [Member]
Condensed Financial Statements, Captions [Line Items]                                                                  
Net income $ 112,200 $ 111,900 $ 132,000 $ 107,900 $ 110,100 $ 107,500 $ 108,600 $ 88,800 $ 463,962 $ 414,959 $ 292,883 $ 117,881 $ 117,779 $ 133,368 $ 108,162 $ 105,357 $ 108,022 $ 111,180 $ 88,019 $ 477,190 $ 412,578 $ 299,215 $ 112,207 $ 111,873 $ 131,951 $ 107,931 $ 110,072 $ 107,459 $ 108,601 $ 88,827 $ 463,962 $ 414,959 $ 292,883
Excess tax benefits from share-based payment arrangements                 (29,684) (26,241) (8,937)                 (29,684) (27,450) (7,728)                 (29,684) (26,241) (8,937)
Deferred income taxes                 (7,758) (21,271) (33,338)                 (9,050) (12,984) (33,313)                 (7,758) (21,271) (33,338)
Income taxes                 28,042 48,565 (2,450)                 16,106 42,659 (8,807)                 28,042 48,565 (2,450)
Net cash provided by operating activities                 567,784 510,540 387,875                 567,784 509,331 389,084                 567,784 510,540 387,875
Excess tax benefits from share-based payment arrangements                 29,684 26,241 8,937                 29,684 27,450 7,728                 29,684 26,241 8,937
Net cash used in financing activities                 $ (371,241) $ (339,008) $ (261,953)                 $ (371,241) $ (337,799) $ (263,162)                 $ (371,241) $ (339,008) $ (261,953)