Stockholders' Equity (Details Textual) - USD ($) $ in Thousands							6 Months Ended		12 Months Ended	51 Months Ended
	Jan. 01, 2019	Jan. 01, 2018	Jan. 01, 2017	Jan. 01, 2016	Jun. 30, 2015	Nov. 14, 2013	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2013	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)							0
Capital shares reserved for future issuance, annual increase, maximum	1,183,075	1,125,846	1,072,870	1,042,766
Exercises in period, intrinsic value							$ 8,570
Restricted Stock Units and Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Antidilutive securities excluded from computation of Earnings Per Share, amount							3,312,492	3,463,645
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized							$ 54
Compensation cost not yet recognized, period for recognition							7 months 4 days
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized							$ 117,850
Compensation cost not yet recognized, period for recognition							2 years 9 months 15 days
The 2005 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)									4,713,319
Vesting period (in years)									4 years
Granted (in shares)										0
Shares available for grant							0
The 2013 Omnibus Equity Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)						1,904,633
Percentage of outstanding stock reserved for grant						4.00%
Percentage of outstanding stock maximum						5.00%
The 2013 Omnibus Equity Award Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						4 years
2015 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum employee subscription rate					15.00%
Purchase price of common stock, percent					85.00%
Number of shares authorized					500,000
Percent of shares increase, employee stock purchase plan					1.00%
Common stock availability threshold, Employee Stock Purchase Plan					2.00%
Shares increase threshold, employee stock purchase plan					400,000
Number of additional shares authorized	177,358	188,813	158,695	21,383