Financial Information Form 10-K Filing date View Feb 07, 2019 View HTML 0000101829-19-000007.pdf 0000101829-19-000007.xls EX-101.INS - XBRL INSTANCE DOCUMENT Feb 09, 2018 View HTML 0000101829-18-000005.pdf 0000101829-18-000005.xls EX-101.INS - XBRL INSTANCE DOCUMENT Form 10-Q Filing date View Jul 26, 2019 View HTML 0000101829-19-000038.pdf 0000101829-19-000038.xls EX-101.SCH - XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT Apr 26, 2019 View HTML 0000101829-19-000016.pdf 0000101829-19-000016.xls EX-101.INS - XBRL INSTANCE DOCUMENT