Annual report pursuant to Section 13 and 15(d)

401(k) Plan and Profit Sharing Plan (Details)

v3.3.1.900
401(k) Plan and Profit Sharing Plan (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Vesting period for profit sharing 2 years    
401(k) [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined contribution plan expense $ 4,800 $ 4,000 $ 3,700
Profit Sharing Plan [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined contribution plan expense $ 0 $ 190 $ 175