Share-Based Compensation and Capital Stock Narrative (Details) (USD $)	0 Months Ended	9 Months Ended		0 Months Ended	9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended						3 Months Ended		9 Months Ended				0 Months Ended			9 Months Ended		0 Months Ended
	Sep. 14, 2012	Sep. 30, 2012	Sep. 30, 2011	Oct. 12, 2012 Dividend Paid [Member]	Sep. 30, 2012 Parent [Member]	Sep. 30, 2011 Parent [Member]	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2011 Stock Options [Member]	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2011 Stock Options [Member]	Sep. 30, 2012 Performance Vested Restricted Stock Units [Member]	Sep. 30, 2011 Performance Vested Restricted Stock Units [Member]	Sep. 30, 2012 Performance Vested Restricted Stock Units [Member]	Sep. 30, 2011 Performance Vested Restricted Stock Units [Member]	Sep. 30, 2012 Performance Vested Restricted Stock Units [Member] Minimum [Member]	Sep. 30, 2012 Performance Vested Restricted Stock Units [Member] Maximum [Member]	Sep. 30, 2011 Performance Vested Restricted Stock Units [Member] Forfeited Based Upon Minimum Performance Conditions [Member]	Sep. 30, 2011 Performance Vested Restricted Stock Units [Member] Forfeited Based Upon Termination [Member]	Sep. 30, 2012 Stock Repurchase Program [Member]	Sep. 30, 2011 Stock Repurchase Program [Member]	Sep. 30, 2012 Stock Repurchase Program [Member]	Sep. 30, 2011 Stock Repurchase Program [Member]	Sep. 30, 2012 Dividend Paid [Member]	Sep. 30, 2011 Dividend Paid [Member]	Oct. 12, 2012 Dividend Paid [Member]	Aug. 23, 2012 2012 Special Cash Dividend [Member]	Jul. 27, 2012 2012 Special Cash Dividend [Member]	Sep. 30, 2012 Quarterly [Member]	Sep. 30, 2011 Quarterly [Member]	Aug. 23, 2012 2012 Special Cash Dividend [Member]
Frequency of cash dividends paid		quarterly	quarterly
Cash dividends paid per share				$ 0.185																								$ 0.185	$ 0.185
Dividends paid		$ 632,751,000	$ 32,923,000		$ 632,751,000	$ 32,923,000																	$ 32,100,000	$ 32,900,000	$ 10,700,000
Special dividends declared per share																											$ 10.41
Special dividends paid per share																										$ 10.41
Special dividends paid																														600,700,000
Cash dividends declared per share	$ 0.185
Options granted							0	0	160,408	166,306
Options granted, fair value									1,600,000	2,100,000
Aggregate intrinsic value of stock options, outstanding							14,300,000		14,300,000
Aggregate intrinsic value of stock options, exercisable							10,600,000		10,600,000
Total intrinsic value of options exercised							500,000	200,000	1,000,000	2,500,000
Proceeds from exercise of stock options		4,695,000	3,726,000		4,695,000	3,726,000	4,300,000	600,000	4,700,000	3,700,000
Stock options exercised							109,996	26,614	135,200	164,150
Stock option adjustment due to special dividend									497,497				0
Percentage adjustment to stock option exercise price due to special dividend									24.00%
Stock-based award vesting range percentage															0.00%	200.00%
Vesting percentage for stock-based award target achievement, minimum															100.00%	160.00%
Grants vested											0	0	0	0
Stock units forfeited											0	0	57,176	41,512			39,070	2,442
Common stock purchased under stock repurchase program, share																			0	700,000	500,000	700,000
Common stock purchased under stock repurchase program, value																				22,200,000	19,900,000	22,200,000
Common stock redeemed, shares																			1,525	3,309	64,037	67,336
Common stock redeemed, value																			$ 100,000	$ 100,000	$ 2,300,000	$ 2,600,000