Organization and Summary of Significant Accounting Policies (Condensed) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) Test country $ / shares shares	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Revenue Recognition
Minimum number of Oncotype DX tests by exclusive distribution agreements | Test			1
Minimum number of countries covered for distribution agreements establishment | country			90
Accrued refunds	$ 447,000		$ 447,000		$ 609,000
Allowance for Doubtful Accounts
Allowance for doubtful accounts	4,113,000		4,113,000		$ 3,988,000
Write-offs for doubtful accounts recorded against allowance	1,800,000	$ 1,300,000	4,200,000	$ 2,300,000
Bad debt expense	2,200,000	$ 1,600,000	4,500,000	$ 2,700,000
Marketable Securities
Proceeds from sales of marketable securities			5,117,000
Realized gains on available-for-sale marketable securities	676,000		2,009,000
Amount reclassified out of accumulated other comprehensive income	345,000		$ 787,000
Common Stock | Sale | Invitae
Marketable Securities
Number of shares of cost method investment sold by entity | shares			495,188
Proceeds from sales of marketable securities			$ 5,100,000
Cost per share (in dollars per share) | $ / shares			$ 6.28
Realized gains on available-for-sale marketable securities			$ 2,000,000
Fair value	12,700,000		12,700,000
Carry value	$ 10,700,000		10,700,000
Amount reclassified out of accumulated other comprehensive income			787,000
Amount reclassified out of accumulated other comprehensive income, tax portion			$ 448,000