Equity Incentive Plans - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Shares
Options outstanding, Beginning Balance, Shares	1,211
Options granted, Shares	461
Options exercised, Shares	(308)
Options forfeited/canceled/expired, Shares	(23)
Options outstanding, Ending Balance, Shares	1,341	1,211
Options vested and expected to vest, ending balance, Shares	661
Options exercisable, ending balance, Shares	585
Wtd. Avg. Exercise Price
Options outstanding, Beginning Balance, Wtd. Avg. Exercise Price (in dollars per share)	$ 20.65
Options granted, Wtd. Avg. Exercise Price (in dollars per share)	32.27
Options exercised, Wtd. Avg. Exercise Price (in dollars per share)	19.81
Options forfeited/canceled/expired, Wtd. Avg. Exercise Price (in dollars per share)	24.86
Options outstanding, Ending Balance, Wtd. Avg. Exercise Price (in dollars per share)	24.76	$ 20.65
Options vested and expected to vest, ending balance, Wtd. Avg. Exercise Price (in dollars per share)	24.52
Options exercisable, ending balance, Wtd. Avg. Exercise Price (in dollars per share)	$ 21.53
Options, Additional Disclosures
Options outstanding, Remaining Contractual Term	7 years 8 months 52 days	7 years 1 month 21 days
Options vested and expected to vest, ending balance, Wtd. Avg., Remaining Contractual Term	7 years 7 months 45 days
Options exercisable, ending balance, Wtd. Avg. Remaining Contractual Term	6 years 5 months 8 days
Options outstanding, Aggregate Intrinsic Value	$ 7,675	$ 5,466
Options vested and expected to vest, ending balance, Aggregate Intrinsic Value	7,373
Options exercisable, ending balance, Aggregate Intrinsic Value	$ 4,946