Share-Based Compensation, Options Activity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
General disclosures [Abstract]
Weighted-average grant-date fair value (in dollars per share)	$ 10.74
Stock Options [Member]
Weighted average valuation assumptions [Abstract]
Expected volatility (in hundredths)	31.77%
Risk-free interest rate (in hundredths)	1.20%
Dividend yield (in hundredths)	2.70%
Expected term (in years)	6.1
Activity in the Company's stock option plans [Roll Forward]
Outstanding, beginning of period (in shares)	2,554,000
Granted (in shares)	132,681
Exercised (in shares)	(391,000)
Forfeited and expired (in shares)	(4,000)
Outstanding, end of period (in shares)	2,292,000
Exercisable (in shares)	1,808,000
Stock option plans, additional disclosures [Abstract]
Outstanding, weighted average exercise price, beginning of period (in dollars per share)	$ 38.39
Granted, weighted average exercise price (in dollars per share)	$ 46.27
Exercised, weighted average exercise price (in dollars per share)	$ 28.27
Forfeited and expired, weighted average exercise price (in dollars per share)	$ 38.79
Outstanding, weighted average exercise price, end of period (in dollars per share)	$ 40.57
Exercisable, weighted average exercise price (in dollars per share)	$ 40.68
Outstanding, weighted average contractual life (in years)	5.4
Exercisable, weighted average contractual life (in years)	4.5
Outstanding, aggregate intrinsic value	$ 18,540
Exercisable, aggregate intrinsic value	$ 14,569
2007 Plan [Member] | Stock Options [Member]
Activity in the Company's stock option plans [Roll Forward]
Outstanding, beginning of period (in shares)	1,545,000
Granted (in shares)	132,681
Exercised (in shares)	(253,000)
Forfeited and expired (in shares)	(3,000)
Outstanding, end of period (in shares)	1,422,000
Exercisable (in shares)	938,000
Predecessor Plan 1998 Employee Plan [Member] | Stock Options [Member]
Activity in the Company's stock option plans [Roll Forward]
Outstanding, beginning of period (in shares)	836,000
Granted (in shares)	0
Exercised (in shares)	(121,000)
Forfeited and expired (in shares)	(1,000)
Outstanding, end of period (in shares)	714,000
Exercisable (in shares)	714,000
Predecessor Plan 1998 Directors' Plan [Member] | Stock Options [Member]
Activity in the Company's stock option plans [Roll Forward]
Outstanding, beginning of period (in shares)	173,000
Granted (in shares)	0
Exercised (in shares)	(17,000)
Forfeited and expired (in shares)	0
Outstanding, end of period (in shares)	156,000
Exercisable (in shares)	156,000