Income Taxes - Effective Income Tax Rate (Details)		12 Months Ended
	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation between the U.S. corporate income tax rate and the effective income tax rate from continuing operations
U.S. corporate income tax rate (as a percent)		35.00%	35.00%	35.00%
Impact of the Tax Cuts and Jobs Act (as a percent)		(25.00%)
Dividends received deduction (as a percent)		(8.00%)	(10.00%)	(11.00%)
Impact of equity method presentation (as a percent)		(2.00%)	(3.00%)	(3.00%)
Tax credits (as a percent)		(2.00%)	(2.00%)	(2.00%)
Interest exclusion from taxable income (as a percent)		(1.00%)	(1.00%)	(1.00%)
State income taxes (as a percent)		2.00%
Merger of Chilean legal entities (as a percent)				(7.00%)
Impact of court ruling on some uncertain tax positions (as a percent)				3.00%
Other income tax rate impacts (as a percent)		(2.00%)	(5.00%)	(2.00%)
Effective income tax rate (as a percent)		(3.00%)	14.00%	12.00%
Forecast
Reconciliation between the U.S. corporate income tax rate and the effective income tax rate from continuing operations
U.S. corporate income tax rate (as a percent)	21.00%