Share-Based Compensation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-Based Compensation [Abstract]
Percent of market price	100.00%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available to be granted under existing stock plans (in shares)	1,200
Aggregate Intrinsic Value [Abstract]
Age participant attains for recognition of expenses from date of grant	65 years
Grant Date Weighted Average Fair Value [Abstract]
Total pre-tax share-based compensation recognized in the Consolidated Statements of Earnings	$ 1,600	$ 6,300	$ 8,400
Tax related benefits	1,400	2,400	2,600
Cash received from the exercise of stock options	$ 400	$ 600	$ 1,000
Range of Exercise Price 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range (in dollars per share)	$ 19.03
Exercise price range, upper range (in dollars per share)	$ 24.14
Options outstanding (in shares)	12
Weighted average remaining contractual life, in years	2 months 12 days
Weighted average exercise price (in dollars per share)	$ 19.64
Options exercisable (in shares)	12
Weighted average exercise price (in dollars per share)	$ 19.64
Range of Exercise Price 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range (in dollars per share)	24.15
Exercise price range, upper range (in dollars per share)	$ 26.11
Options outstanding (in shares)	12
Weighted average remaining contractual life, in years	1 year 1 month 6 days
Weighted average exercise price (in dollars per share)	$ 24.35
Options exercisable (in shares)	12
Weighted average exercise price (in dollars per share)	$ 24.35
Range of Exercise Price 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range (in dollars per share)	26.12
Exercise price range, upper range (in dollars per share)	$ 30.07
Options outstanding (in shares)	21
Weighted average remaining contractual life, in years	1 year 9 months 18 days
Weighted average exercise price (in dollars per share)	$ 28.16
Options exercisable (in shares)	21
Weighted average exercise price (in dollars per share)	$ 28.16
Non-vested Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognition period	5 years
Aggregate Intrinsic Value [Abstract]
Percentage of future grants that will be performance stock unit awards	100.00%	100.00%	50.00%
Percentage of future grants that will be time vesting stock unit awards			50.00%
Percentage of stated performance metrics award of grant	150.00%	150.00%	150.00%
Number of years to measure performance metrics	3 years	3 years	2 years
Non-vested Stock [Roll Forward]
Outstanding, beginning of period (in shares)	604	497	339
Granted (in shares)	154	171	262
Vested (in shares)	(74)	(40)	(94)
Cancelled (in shares)	(142)	(24)	(10)
Outstanding, end of period (in shares)	542	604	497	339
Grant Date Weighted Average Fair Value [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 43.84	$ 38.46	$ 33.22
Granted (in dollars per share)	60.65	55.21	46.14
Vested (in dollars per share)	35.51	27.15	40.57
Cancelled (in dollars per share)	47.02	40.84	42.22
Outstanding, end of period (in dollars per share)	$ 48.94	$ 43.84	$ 38.46	$ 33.22
Outstanding, aggregate intrinsic value	$ 34,063	$ 36,454	$ 24,095	$ 12,046
Total intrinsic values of shares vested	$ 4,800	$ 2,200	$ 4,400
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (in shares)	0	0	0
Expense recognition period	3 years
Expiration from date of grant	10 years
Stock Options [Roll Forward]
Outstanding, beginning of period (in shares)	66	93	141
Exercised (in shares)	(21)	(27)	(48)
Outstanding, end of period (in shares)	45	66	93	141
Exercisable, end of period (in shares)	45
Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 23.49	$ 23.04	$ 22.35
Exercised (in dollars per share)	20.59	21.92	21.00
Outstanding, end of period (in dollars per share)	24.84	$ 23.49	$ 23.04	$ 22.35
Exercisable, end of period (in dollars per share)	$ 24.84
Weighted Average Remaining Life [Abstract]
Outstanding	1 year 2 months 12 days	1 year 8 months 12 days	2 years 2 months 12 days	2 years 8 months 12 days
Exercisable	1 year 2 months 12 days
Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value, outstanding	$ 1,715	$ 2,438	$ 2,374	$ 1,859
Aggregate intrinsic value, exercisable	1,715
Aggregate intrinsic values of stock options exercised	900	$ 800	$ 1,100
Non-vested Stock and Performance Stock Units [Member]
Grant Date Weighted Average Fair Value [Abstract]
Compensation cost net yet recognized	$ 14,900
Compensation cost not yet recognized, period for recognition	1 year 8 months 5 days