Shareholders' Equity (Details)			12 Months Ended
	Oct. 28, 2013 $ / shares	Feb. 29, 2012 $ / shares	Dec. 31, 2016 USD ($) plans $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends per share of common stock (in dollars per share) | $ / shares	$ 0.20	$ 0.15	$ 0.80	$ 0.80	$ 0.80
Dividends payable			$ 5,566,000	$ 5,542,000	$ 5,510,000
Preferred stock, shares authorized | shares			500,000	500,000
Preferred stock, par value (in dollars per per share) | $ / shares			$ 0.01	$ 0.01
Shares authorized under repurchase program			$ 200,000,000.0
Total stock repurchased under plan, shares | shares			6,100,000
Total stock repurchased under plan, value			$ 162,600,000
Remaining authorized repurchase amount			$ 37,400,000
Number of share repurchased | shares					400,000.0
Repurchase of treasury stock					$ 16,862,000
Number of shares reserved for share-based compensation plans | shares			8,900,000
Number of share-based compensation plans | plans			3
Number of shares available for grant | shares			1,500,000
Vesting term (in years)			5 years
Stock-based compensation			$ 8,375,000	$ 7,499,000	9,330,000
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost			700,000	1,000,000	3,900,000
Tax benefit from stock-based compensation			3,100,000	2,700,000	3,400,000
Proceeds from stock options exercised			$ 0	$ 200,000	$ 1,800,000
Stock Options and Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period from date of grant (in years)			10 years