Cash and Cash Equivalents, and Marketable Securities (Invitae) (Details)	3 Months Ended
	Mar. 31, 2017 USD ($) $ / shares
Disposal
Amount reclassified out of accumulated other comprehensive income	$ 1,126,000
Invitae | Sale | Common Stock
Disposal
Proceeds from sales of marketable securities	$ 10,200,000
Cost per share (in dollars per share) | $ / shares	$ 6.28
Realized gains on available-for-sale marketable securities	$ 2,800,000
Amount reclassified out of accumulated other comprehensive income	1,100,000
Amount reclassified out of accumulated other comprehensive income, tax portion	$ 821,000