Employee Benefit Obligations - Summary of Expected Flow for Benefits for Next Five Years (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017 CLP ($)
Less than one year [Member]
Disclosure Of Defined Benefit Plans [Line Items]
Estimate of contributions expected to be paid to plan	$ 1,914,503
One to Two Years [Member]
Disclosure Of Defined Benefit Plans [Line Items]
Estimate of contributions expected to be paid to plan	1,548,303
Two to Three Years [Member]
Disclosure Of Defined Benefit Plans [Line Items]
Estimate of contributions expected to be paid to plan	1,060,730
Three to Four Years [Member]
Disclosure Of Defined Benefit Plans [Line Items]
Estimate of contributions expected to be paid to plan	1,718,533
Four to Five Years [Member]
Disclosure Of Defined Benefit Plans [Line Items]
Estimate of contributions expected to be paid to plan	1,319,346
Over five years [Member]
Disclosure Of Defined Benefit Plans [Line Items]
Estimate of contributions expected to be paid to plan	$ 5,859,301