Revenue Recognition - Schedule of Product Sales Allowances and Accruals (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Provision related to current period sales									$ 500	$ 700
Total revenues	$ 224,344	$ 228,772	$ 226,368	$ 222,451	$ 221,852	$ 249,815	$ 263,685	$ 254,914	901,935	990,266	$ 966,006
Rayaldee
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance				4,043				1,018	4,043	1,018
Provision related to current period sales									42,528	16,445
Credits or payments made									(34,785)	(13,420)
Ending balance	11,786				4,043				11,786	4,043	1,018
Total revenues									$ 73,965	$ 36,715
Provision for Rayaldee sales allowances and accruals as a percentage of gross Rayaldee sales									57.00%	45.00%
Chargebacks, discounts, rebates and fees | Rayaldee
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance				1,316				233	$ 1,316	$ 233
Provision related to current period sales									13,723	5,704
Credits or payments made									(11,845)	(4,621)
Ending balance	3,194				1,316				3,194	1,316	233
Governmental | Rayaldee
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance				2,090				348	2,090	348
Provision related to current period sales									25,106	10,061
Credits or payments made									(21,355)	(8,319)
Ending balance	5,841				2,090				5,841	2,090	348
Returns | Rayaldee
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance				$ 637				$ 437	637	437
Provision related to current period sales									3,699	680
Credits or payments made									(1,585)	(480)
Ending balance	$ 2,751				$ 637				$ 2,751	$ 637	$ 437