Significant Accounting Policies - Additional Information (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($) shares	Sep. 30, 2019 USD ($) Segment shares	Jun. 30, 2019 USD ($)	May 16, 2019 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Significant Accounting Policies [Line Items]
Number of operating segment | Segment		1
Debt and capital lease obligations	$ 45,000,000	$ 45,000,000				$ 45,000,000
Long-term debt, fair value	46,200,000	46,200,000				$ 45,600,000
Operating lease, right-of-use asset	$ 67,400,000	$ 67,400,000
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Operating lease, liability	$ 68,553,000	$ 68,553,000
Accounting Standards Update 2016-02 [Member]
Significant Accounting Policies [Line Items]
Operating lease, right-of-use asset					$ 68,000,000.0
Operating lease, liability					$ 69,100,000
2018 Share Repurchase Program [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Stock repurchase program, authorized amount			$ 250,000,000.0
2019 Share Repurchase Program [Member]
Significant Accounting Policies [Line Items]
Stock repurchased and retired during period, shares | shares	254,294	1,406,208
Stock repurchased and retired during period, value	$ 40,600,000	$ 205,300,000
Stock repurchase program, remaining authorized repurchase amount	$ 276,400,000	$ 276,400,000
2019 Share Repurchase Program [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Stock repurchase program, authorized amount				$ 350,000,000.0