Stock Incentive Compensation and Employee Benefit Plans (Schedule of Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
2001 Stock Incentive Plans and Nonemployee Directors
Weighted options outstanding:
Balance, Beginning of Period (shares)	828,092	1,732,639	1,973,307
Options granted (in shares)	0	0	0
Options forfeited (in shares)	0	0	0
Options expired (in shares)	0	0	0
Options exercised (in shares)	(60,262)	(904,547)	(240,668)
Balance, End of Period (shares)	767,830	828,092	1,732,639	1,973,307
Weighted average exercise price:
Weighted average exercise price, Beginning of Period (In dollars per share)	$ 48.77	$ 47.61	$ 47.33
Options granted, Weighted average exercise price (In dollars per share)	$ 0.00	$ 0.00	$ 0.00
Options forfeited, Weighted average exercise price (In dollars per share)	$ 0.00	$ 0.00	$ 0.00
Options expired, Weighted average exercise price (In dollars per share)	$ 0.00	$ 0.00	$ 0.00
Options exercised, Weighted average exercise price (In dollars per share)	$ 49.52	$ 46.55	$ 45.30
Weighted average exercise price, End of Period (In dollars per share)	$ 48.71	$ 48.77	$ 47.61	$ 47.33
Weighted average remaining contractual life	2 years	2 years 10 months 24 days	3 years 8 months	4 years 7 months
Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value	$ 37,246	$ 40,221	$ 58,305	$ 53,363
Options exercised, Aggregate intrinsic value	2,900	36,800	7,910
Range of Exercise Prices [Abstract]
Exercise price range, lower range limit (In dollars per share)	$ 37.51	$ 37.51	$ 37.51	$ 37.51
Exercise price range, upper range limit (In dollars per share)	$ 59.66	$ 59.66	$ 59.66	$ 59.66
Total options exercisable, minimum (In dollars per share)	$ 37.51
Total options exercisable, maximum (In dollars per share)	$ 59.66
Total options exercisable (in shares)	767,830
Total options exercisable, Weighted average exercise price (In dollars per share)	$ 48.71
Total options exercisable, Weighted average remaining contractual life	2 years
Total options exercisable, Aggregate intrinsic value	37,246
Premium Option Plan
Weighted options outstanding:
Balance, Beginning of Period (shares)	572,000	842,000	1,192,000
Options granted (in shares)	0	0	0
Options forfeited (in shares)	0	0	0
Options expired (in shares)	0	0	0
Options exercised (in shares)	(572,000)	(270,000)	(350,000)
Balance, End of Period (shares)	0	572,000	842,000	1,192,000
Weighted average exercise price:
Weighted average exercise price, Beginning of Period (In dollars per share)	$ 73.62	$ 73.82	$ 73.94
Options granted, Weighted average exercise price (In dollars per share)	$ 0.00	$ 0.00	$ 0.00
Options forfeited, Weighted average exercise price (In dollars per share)	$ 0.00	$ 0.00	$ 0.00
Options expired, Weighted average exercise price (In dollars per share)	$ 0.00	$ 0.00	$ 0.00
Options exercised, Weighted average exercise price (In dollars per share)	$ 73.62	$ 74.24	$ 74.24
Weighted average exercise price, End of Period (In dollars per share)	$ 0.00	$ 73.62	$ 73.82	$ 73.94
Weighted average remaining contractual life	0 years
Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value	0	13,567	6,265	0
Options exercised, Aggregate intrinsic value	13,414	4,921	1,250
Range of Exercise Prices [Abstract]
Exercise price range, lower range limit (In dollars per share)	$ 0	$ 73.06	$ 73.06	$ 73.06
Exercise price range, upper range limit (In dollars per share)	$ 0	$ 74.24	$ 74.24	$ 74.24
Total options exercisable, minimum (In dollars per share)	$ 0
Total options exercisable, maximum (In dollars per share)	$ 0
Total options exercisable (in shares)	0
Total options exercisable, Weighted average exercise price (In dollars per share)	$ 0.00
Total options exercisable, Weighted average remaining contractual life	0 years
Total options exercisable, Aggregate intrinsic value	$ 0

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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