Organization and Summary of Significant Accounting Policies - Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle
Package of practical expedients	true
Assets
Other current assets	$ 14,615			$ 12,961	$ 18,731
Total current assets	285,633			320,130	325,900
Property, plant and equipment, net	84,490			81,421	89,489
Other intangible assets, net	17,985			15,258	15,478
Deferred income taxes	68,581			65,065	65,635
Operating lease right-of-use assets	109,838			103,378
Other assets	8,537			8,304	7,766
Total assets	801,412			792,298	703,010
Current liabilities:
Current portion of long-term debt	8,619			7,964	8,583
Accrued expenses and other current liabilities	55,908			50,431	51,783
Current portion of operating lease liabilities	32,437			31,479
Total current liabilities	190,428			200,782	171,274
Long-term liabilities:
Long-term debt, less current portion	488,620			489,597	502,090
Operating lease liabilities	88,719			83,662
Other liabilities	47,851			38,620	51,570
Total liabilities	815,618			812,661	724,934
Shareholders' deficit:
Accumulated deficit	(350,687)			(359,462)	(361,023)
Total shareholders' deficit	(14,206)	$ (21,830)	$ (30,605)	(20,363)	(21,924)	$ (25,604)	$ (35,300)	$ (53,575)	$ (28,810)	$ (28,051)
Total liabilities and shareholders' deficit	801,412			792,298	$ 703,010
Capitalized implementation costs	$ 314
ASU 2016-02 | Restatement Adjustments
Assets
Other current assets				(5,770)
Total current assets				(5,770)
Property, plant and equipment, net				(8,068)
Other intangible assets, net				(220)
Deferred income taxes				(570)
Operating lease right-of-use assets				103,378
Other assets				538
Total assets				89,288
Current liabilities:
Current portion of long-term debt				(619)
Accrued expenses and other current liabilities				(1,352)
Current portion of operating lease liabilities				31,479
Total current liabilities				29,508
Long-term liabilities:
Long-term debt, less current portion				(12,493)
Operating lease liabilities				83,662
Other liabilities				(12,950)
Total liabilities				87,727
Shareholders' deficit:
Accumulated deficit				1,561
Total shareholders' deficit				1,561
Total liabilities and shareholders' deficit				$ 89,288