Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 29, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jul. 01, 2017		Apr. 01, 2017		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Earnings Per Share, Diluted [Line Items]
Net income attributable to shareholders	$ 230,653	[1]	$ 176,533		$ 169,915		$ 139,094		$ 53,653	[1]	$ 134,064		$ 99,722	[2]	$ 114,737		$ 716,195		$ 402,176		$ 522,815
Weight-average shares outstanding - basic																	87,476		88,681		90,960
Net effect of various dilutive stock-based compensation awards																	968		1,085		1,073
Weighted average shares outstanding - diluted																	88,444		89,766		92,033
Net Income per Share [Abstract]
Basic	$ 2.66	[3]	$ 2.02	[3]	$ 1.94	[3]	$ 1.58	[3]	$ 0.61	[3]	$ 1.52	[3]	$ 1.12	[3]	$ 1.29	[3]	$ 8.19		$ 4.54		$ 5.75
Diluted	$ 2.63	[3]	$ 1.99	[3]	$ 1.92	[3]	$ 1.56	[3]	$ 0.60	[3]	$ 1.50	[3]	$ 1.11	[3]	$ 1.27	[3]	$ 8.10	[4]	$ 4.48	[4]	$ 5.68	[4]
Stock Compensation Plan [Member]
Net Income per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount																	651		380		766

[1] Net income attributable to shareholders includes a U.S. Tax Act benefit of $28.3 million and expense of $124.7 million during the fourth quarter of 2018 and 2017, respectively.

[2] Net income attributable to shareholders includes a loss on extinguishment of debt of $58.8 million during the second quarter of 2017.

[3] Quarterly net income per share is calculated using the weighted-average shares outstanding during each quarterly period, while net income per share for the full year is calculated using the weighted-average shares outstanding during the year. Therefore, the sum of the net income per share for each of the four quarters may not equal the net income per share for the full year.

[4] Stock-based compensation awards for the issuance of 651 shares, 380 shares, and 766 shares for the years ended December 31, 2018, 2017, and 2016, respectively, were excluded from the computation of net income per share on a diluted basis as their effect was anti-dilutive.