Share-Based Compensation and Capital Stock - Narrative (Details) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended												9 Months Ended	12 Months Ended					222 Months Ended
	Jan. 01, 2014 shares	Oct. 31, 2005	Dec. 31, 2016 USD ($) $ / shares shares	Sep. 30, 2016 $ / shares	Jun. 30, 2016 $ / shares	Mar. 31, 2016 $ / shares	Dec. 31, 2015 $ / shares	Sep. 30, 2015 $ / shares	Jun. 30, 2015 $ / shares	Mar. 31, 2015 $ / shares	Dec. 31, 2014 $ / shares	Sep. 30, 2014 $ / shares	Jun. 30, 2014 $ / shares	Mar. 31, 2014 $ / shares	Sep. 30, 2014 $ / shares	Dec. 31, 2016 USD ($) $ / shares shares		Dec. 31, 2015 USD ($) $ / shares shares		Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual amount, per share, of dividends declared (in dollars per share) | $ / shares								$ 0.195
Dividends declared																$ 46,708		$ 45,531		$ 43,784
Number of shares authorized | shares			7,600,000													7,600,000					7,600,000
Number of shares available for grant | shares			1,200,000													1,200,000					1,200,000
Options granted, shares | shares																745,769		498,911		651,757
Options granted, fair value																$ 6,900		$ 6,200		$ 5,700
Aggregate intrinsic value of stock, options, outstanding			$ 20,400													20,400					$ 20,400
Aggregate intrinsic value of the stock options, exercisable			$ 13,300													13,300					$ 13,300
Total intrinsic value of options exercised																12,600		10,500		10,100
Proceeds from exercise of stock options																$ 12,951		$ 7,056		$ 10,098
Stock options exercised | shares																529,210		295,037		390,290
Stock-based compensation expense																$ 14,600		$ 12,100		$ 9,400
Stock repurchased during period, shares | shares																600,000					48,700,000
Common stock purchased under stock repurchase program, value																$ 30,100					$ 1,300,000
Common stock split, conversion ratio		2
Shares paid for tax withholding for share-based compensation | shares																127,036		106,405		110,579
Payments related to tax withholding for share-based compensation																$ 5,800		$ 6,400		$ 5,300
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Frequency of dividend payments																quarterly
Common Stock Dividends, periodic payment, Per Share | $ / shares																$ 0.215
Annual amount, per share, of dividends declared (in dollars per share) | $ / shares			$ 0.215	$ 0.205	$ 0.205	$ 0.205	$ 0.205	$ 0.195	$ 0.195	$ 0.195	$ 0.195	$ 0.185	$ 0.185	$ 0.185	$ 0.185	$ 0.83		$ 0.79		$ 0.75
Dividends declared																$ 46,700		$ 45,100		$ 43,400
Decrease to shares outstanding, reconciliation | shares	300,000																	0		341,278
Prior To Stock Split
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchased during period, shares | shares																					33,000,000
Family Member(s) of Largest Shareholder
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchased during period, shares | shares																		1,300,000		1,399,491
Common stock purchased under stock repurchase program, value																		$ 66,400		$ 72,600
Performance Vested Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends declared																$ 100		$ 500		$ 400
Grants vested (shares) | shares																28,188		42,326		28,886
Grant date fair value of shares vested																$ 1,000		$ 1,500		$ 1,400
Grants vested, initial target (shares) | shares																48,201		38,476		18,635
Performance based leveraging decrease (in shares) | shares																(20,013)
Grants vested, percentage																		110.00%		155.00%
Performance-based leveraging (in shares) | shares																2,043	[1]	3,850	[2]	10,251
Stock units forfeited (in shares) | shares																54,556		6,079		22,099
Stock-based compensation expense																$ 2,500		$ 1,900		$ (200)
Performance Vested Restricted Stock Units | Adjustment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense																$ 100		$ 300		$ (1,300)
Performance Vested Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting range																0.00%
Vesting percentage for stock-based award target achievement																0.00%
Performance Vested Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting range																200.00%
Vesting percentage for stock-based award target achievement																175.00%

[1] PVRSU units outstanding have been increased by 2,043 units during the year ended December 31, 2016, due to the Company exceeding the targeted performance conditions contained in PVRSU's granted in prior periods

[2] PVRSU units outstanding have been increased by 3,850 units during the year ended December 31, 2015, due to the Company exceeding the targeted performance conditions contained in PVRSU's granted in prior periods.