Annual report pursuant to Section 13 and 15(d)

Dividends to Shareholders (Details Textual)

v3.6.0.2
Dividends to Shareholders (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 3 Months Ended 12 Months Ended
Feb. 24, 2017
Feb. 28, 2017
Dec. 31, 2016
Oct. 01, 2016
Jul. 02, 2016
Apr. 02, 2016
Jan. 02, 2016
Sep. 26, 2015
Jun. 27, 2015
Mar. 28, 2015
Dec. 27, 2014
Sep. 27, 2014
Jun. 28, 2014
Mar. 29, 2014
Dec. 31, 2016
Jan. 02, 2016
Dec. 27, 2014
Subsequent Event [Line Items]                                  
Dividends declared                             $ 10,757 $ 12,018 $ 38,377
Common Stock, Dividends, Per Share, Declared     $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.090 $ 0.40 $ 0.45 $ 1.45
Dividend paid, date of payment                             Mar. 31, 2016 Mar. 31, 2015 Mar. 31, 2014
Dividend paid, date of record                             Mar. 15, 2016 Mar. 15, 2015 Mar. 15, 2014
Special Dividend [Member]                                  
Subsequent Event [Line Items]                                  
Common Stock, Dividends, Per Share, Declared                             $ 0.04 $ 0.09 $ 0.09
Special One-Time Cash Dividend [Member]                                  
Subsequent Event [Line Items]                                  
Common Stock, Dividends, Per Share, Declared                                 $ 1.00
Dividend paid, date of payment                                 Oct. 24, 2014
Dividend paid, date of record                                 Oct. 10, 2014
Subsequent Event [Member]                                  
Subsequent Event [Line Items]                                  
Common Stock, Dividends, Per Share, Declared $ 0.02 $ 0.02                              
Dividend paid, date of payment Mar. 31, 2017 Mar. 31, 2017                              
Dividend paid, date of record Mar. 15, 2017 Mar. 15, 2017