401(k) and Profit-Sharing Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer Matching Contribution, Percent of Match	50.00%
The Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Maximum Employee Subscription Rate	100.00%
Forfeitures during period	$ 126	$ 118	$ 83
Employer matching contributions	1,464	$ 1,511	$ 1,074
Common stock | Restricted Stock Units (RSUs)
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Allocated Share-based Compensation Expense	$ 32,559