XML 106 R83.htm IDEA: XBRL DOCUMENT v3.8.0.1

Inventories - Narratives (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Business Combinations
Inventory
Difference in LIFO and FIFO inventory valuation	$ 26,630	$ 30,338

X

- Definition

LIFO and FIFO Difference in Inventory Amount

+ References

No definition available.

+ Details

Name:	pqg_LIFOandFIFODifferenceinInventoryValuation
Namespace Prefix:	pqg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_InventoryLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=pqg_BusinessCombinationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: