Share-Based Compensation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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)	1,100
Grant Date Weighted Average Fair Value [Abstract]
Total pre-tax share-based compensation recognized in the Consolidated Statements of Earnings	$ 7,700	$ 1,600	$ 6,300
Tax related benefits	2,800	500	2,400
Cash received from the exercise of stock options	$ 700	$ 400	$ 600
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)	$ 26.12
Exercise price range, upper range (in dollars per share)	$ 30.06
Options outstanding (in shares)	6
Weighted average remaining contractual life, in years	3 months 18 days
Weighted average exercise price (in dollars per share)	$ 26.12
Options exercisable (in shares)	6
Weighted average exercise price (in dollars per share)	$ 26.12
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)	30.07
Exercise price range, upper range (in dollars per share)	$ 30.07
Options outstanding (in shares)	9
Weighted average remaining contractual life, in years	1 year 3 months 18 days
Weighted average exercise price (in dollars per share)	$ 30.07
Options exercisable (in shares)	9
Weighted average exercise price (in dollars per share)	$ 30.07
Non-vested Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognition period	5 years
Aggregate Intrinsic Value [Abstract]
Age participant attains for recognition of expenses from date of grant	65 years
Percentage of future grants that will be performance stock unit awards	100.00%	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%	150.00%
Number of years to measure performance metrics	3 years	3 years	3 years	2 years
Non-vested Stock [Roll Forward]
Outstanding, beginning of period (in shares)	542	604	497
Granted (in shares)	119	154	171
Vested (in shares)	(172)	(74)	(40)
Cancelled (in shares)	(54)	(142)	(24)
Outstanding, end of period (in shares)	435	542	604	497
Grant Date Weighted Average Fair Value [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 48.94	$ 43.84	$ 38.46
Granted (in dollars per share)	69.92	60.65	55.21
Vested (in dollars per share)	43.42	35.51	27.15
Cancelled (in dollars per share)	52.41	47.02	40.84
Outstanding, end of period (in dollars per share)	$ 56.44	$ 48.94	$ 43.84	$ 38.46
Outstanding, aggregate intrinsic value	$ 34,184	$ 34,063	$ 36,454	$ 24,095
Total intrinsic values of shares vested	$ 12,800	$ 4,800	$ 2,200
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)	45	66	93
Exercised (in shares)	(30)	(21)	(27)
Outstanding, end of period (in shares)	15	45	66	93
Exercisable, end of period (in shares)	15
Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 24.84	$ 23.49	$ 23.04
Exercised (in dollars per share)	23.11	20.59	21.92
Outstanding, end of period (in dollars per share)	28.45	$ 24.84	$ 23.49	$ 23.04
Exercisable, end of period (in dollars per share)	$ 28.45
Weighted Average Remaining Life [Abstract]
Outstanding	10 months 24 days	1 year 2 months 12 days	1 year 8 months 12 days	2 years 2 months 12 days
Exercisable	10 months 24 days
Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value, outstanding	$ 735	$ 1,715	$ 2,438	$ 2,374
Aggregate intrinsic value, exercisable	735
Aggregate intrinsic values of stock options exercised	1,300	$ 900	$ 800
Non-vested Stock and Performance Stock Units [Member]
Grant Date Weighted Average Fair Value [Abstract]
Compensation cost net yet recognized	$ 13,600
Compensation cost not yet recognized, period for recognition	1 year 6 months 4 days