Stock-Based Incentive Plans (Details) (USD $)	9 Months Ended		12 Months Ended	0 Months Ended	9 Months Ended						0 Months Ended
	Sep. 30, 2014 plan	Sep. 30, 2013	Dec. 31, 2013	Feb. 03, 2014 Restricted Stock Units	Sep. 30, 2014 Restricted Stock Units		Sep. 30, 2013 Restricted Stock Units	Sep. 30, 2014 Non-Qualified Stock Options		Sep. 30, 2014 Unvested Stock Options	Feb. 03, 2014 Non Employee Directors Restricted Stock Units
Stock-Based Compensation
Number of stock-based incentive plans	1
Number of stock option plans superseded	2
Awarded (in dollars per share)				$ 30.98
Restricted stock unit activity
Outstanding at the beginning of the period (in shares)					448,000
Awarded (in shares)				342,950	343,000						9,975
Vested (in shares)					(282,000)
Forfeited (in shares)					(1,000)
Outstanding at the end of the period (in shares)					508,000
Outstanding and expected to vest at the end of the period (in shares)					497,000
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)					$ 32.45			$ 29.35
Outstanding at the end of the period (in dollars per share)					$ 31.67			$ 29.39
Outstanding and expected to vest at end of the period (in dollars per share)								$ 29.39
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term								3 years 3 months 18 days
Exercisable at end of the period (in dollars per share)								$ 29.33
Weighted-Average Exercise Price
Outstanding and expected to vest at the end of the period (in dollars per share)					$ 31.68
Granted (in shares)	0		0
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)					$ 14,817,000	[1]		$ 212,000	[2]
Outstanding and expected to vest at end of the period (in dollars)					14,473,000	[1]		212,000	[2]
Exercisable at end of the period (in dollars)								212,000	[2]
Total intrinsic value of options exercised (in dollars)	700,000	900,000
Aggregate Intrinsic Value
Total intrinsic value of awards vested (in dollars)					9,000,000		5,700,000
Closing price per share (in dollars per share)					$ 29.15
Non-Qualified Stock Options activity
Outstanding at the beginning of the period (in shares)								1,021,000
Exercised (in shares)								(144,000)
Forfeited (in shares)								(5,000)
Outstanding at the end of the period (in shares)								872,000
Outstanding and expected to vest at the end of the period (in shares)								864,000
Exercisable at the end of the period (in shares)								710,000
Weighted-Average Remaining Contractual Life
Exercisable at end of the period								3 years 2 months 12 days
Number of Shares, Unvested Stock Options
Unvested at the beginning of the period (in shares)										448,000
Vested (in shares)										(285,000)
Forfeited (in shares)										(1,000)
Unvested at the end of the period (in shares)										162,000
Weighted-Average Grant-Date Fair Value, Unvested Stock Options
Unvested at the beginning of the period (in dollars per share)										$ 10.31
Vested (in dollars per share)										$ 10.30
Forfeited (in dollars per share)										$ 10.33
Unvested at the end of the period (in dollars per share)										$ 10.33
Unrecognized compensation cost and vesting period
Unrecognized compensation costs related to unvested share-based compensation arrangements	$ 16,700,000
Weighted-average period for recognition of unrecognized stock-based compensation expense	1 year 9 months 11 days

[1] The intrinsic value is calculated using the closing price per share of $29.15 as reported by the New York Stock Exchange on September 30, 2014.

[2] The intrinsic value represents the amount, if any, by which the fair market value of the underlying common stock exceeds the exercise price of the stock option, using the closing price per share of $29.15 as reported by the New York Stock Exchange on September 30, 2014.