| Date Filed | Type | Description |
| 04/23/2018 |
10-K/A
| Annual Report for the period ended December 31, 2017 [amend] |
| 03/01/2018 |
10-K
| Annual Report for the period ended December 31, 2017 |
| 02/28/2017 |
10-K
| Annual Report for the period ended December 31, 2016 |
| 02/26/2016 |
10-K
| Annual Report for the period ended December 31, 2015 |
| 02/27/2015 |
10-K
| Annual Report for the period ended December 31, 2014 |
| 02/26/2014 |
10-K
| Annual Report for the period ended December 31, 2013 |
| 02/28/2013 |
10-K
| Annual Report for the period ended December 31, 2012 |
| 02/28/2012 |
10-K
| Annual Report for the period ended December 31, 2011 |
| 02/28/2011 |
10-K
| Annual Report for the period ended December 31, 2010 |
| 03/01/2010 |
10-K
| Annual Report for the period ended December 31, 2009 |
| 04/30/2009 |
10-K/A
| Annual Report for the period ended December 31, 2008 [amend] |
| 03/02/2009 |
10-K
| Annual Report for the period ended December 31, 2008 |
| 02/29/2008 |
10-K
| Annual Report for the period ended December 31, 2007 |
| 05/24/2007 |
10-K
| Annual Report for the period ended December 31, 2006 |
| 11/22/2006 |
10-K
| Annual Report for the period ended December 31, 2005 |
| 03/14/2005 |
10-K
| Annual Report for the period ended December 31, 2004 |
| 03/01/2004 |
10-K
| Annual Report for the period ended December 31, 2003 |
| 03/05/2003 |
10-K
| Annual Report for the period ended December 31, 2002 |
| 03/29/2002 |
10-K405
| Form 10-K405 - Annual report [Sections 13 and 15(d), S-K Item 405] |
| 03/30/2001 |
10-K405
| Form 10-K405 - Annual report [Sections 13 and 15(d), S-K Item 405] |
| 03/10/2000 |
10-K
| Annual Report for the period ended December 31, 1999 |
| 08/16/1999 |
10-K/A
| Annual Report for the period ended December 31, 1998 [amend] |
| 03/31/1999 |
10-K
| Annual Report for the period ended December 31, 1998 |
| 10/27/1998 |
10-K/A
| Annual Report for the period ended December 31, 1997 [amend] |
| 10/27/1998 |
10-K/A
| Annual Report for the period ended December 31, 1997 [amend] |
| 03/31/1998 |
10-K
| Annual Report for the period ended December 31, 1997 |
| 07/29/1997 |
10-K
| Annual Report for the period ended December 31, 1996 |
| 03/27/1997 |
10-K/A
| Annual Report for the period ended April 30, 1996 [amend] |
| 07/26/1996 |
10-K
| Annual Report for the period ended April 30, 1996 |
| 07/26/1995 |
10-K405
| Form 10-K405 - Annual report [Sections 13 and 15(d), S-K Item 405] |
| 07/29/1994 |
10-K
| Annual Report for the period ended April 30, 1994 |