Stock-Based Incentive Plans (Details) (USD $)	0 Months Ended	6 Months Ended
	Feb. 03, 2014	Jun. 30, 2014	Jun. 30, 2013
Stock-Based Compensation
Number of stock-based incentive plans		1
Number of stock option plans superseded		2
Aggregate Intrinsic Value
Total intrinsic value of options exercised (in dollars)		$ 500,000	$ 200,000
Granted (in shares)		0	0
Unrecognized compensation cost and vesting period
Unrecognized compensation costs related to unvested share-based compensation arrangements		22,300,000
Weighted-average period for recognition of unrecognized stock-based compensation expense		1 year 10 months 24 days
Restricted Stock Units
Stock-Based Compensation
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
Vested (in shares)		(249,000)
Forfeited (in shares)		(1,000)
Outstanding at the end of the period (in shares)		541,000
Outstanding and expected to vest at the end of the period (in shares)		528,000
Weighted-Average Exercise Price
Outstanding and expected to vest at the end of the period (in dollars per share)		$ 31.69
Aggregate Intrinsic Value
Closing price per share (in dollars per share)		$ 36.36
Total intrinsic value of awards vested (in dollars)		8,000,000	5,500,000
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)		$ 32.48
Outstanding at the end of the period (in dollars per share)		$ 31.68
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)		19,669,000
Outstanding and expected to vest at end of the period (in dollars)		16,745,000
Non-Qualified Stock Options
Weighted-Average Remaining Contractual Life
Outstanding and expected to vest at end of the period		3 years 6 months
Exercisable at end of the period		3 years 6 months
Non-Qualified Stock Options activity
Outstanding at the beginning of the period (in shares)		1,021,000
Exercised (in shares)		(92,000)
Forfeited (in shares)		(5,000)
Outstanding at the end of the period (in shares)		924,000
Outstanding and expected to vest at the end of the period (in shares)		916,000
Exercisable at the end of the period (in shares)		669,000
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)		$ 29.35
Outstanding at the end of the period (in dollars per share)		$ 29.40
Outstanding and expected to vest at end of the period (in dollars per share)		$ 29.40
Exercisable at end of the period (in dollars per share)		$ 29.30
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)		6,436,000
Outstanding and expected to vest at end of the period (in dollars)		6,378,000
Exercisable at end of the period (in dollars)		$ 4,726,000
Unvested Stock Options
Number of Shares, Unvested Stock Options
Unvested at the beginning of the period (in shares)		448,000
Vested (in shares)		(193,000)
Unvested at the end of the period (in shares)		255,000
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)		$ 10.29
Unvested at the end of the period (in dollars per share)		$ 10.33
Non Employee Directors | Restricted Stock Units
Restricted stock unit activity
Awarded (in shares)	9,975