Annual report pursuant to Section 13 and 15(d)

Consolidated Statements of Cash Flows (Parenthetical)

v3.8.0.1
Consolidated Statements of Cash Flows (Parenthetical)
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Jan. 30, 2013
Notes | Notes Due February 1, 2033        
Interest rate of notes payable 3.00% 3.00% 3.00% 3.00%