Quarterly report pursuant to Section 13 or 15(d)

Significant Accounting Policies - Additional Information (Details)

v3.19.2
Significant Accounting Policies - Additional Information (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2019
USD ($)
shares
Jun. 30, 2019
USD ($)
Segment
shares
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 $ 67,300,000 $ 67,300,000      
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] us-gaap:OtherAssetsNoncurrent us-gaap:OtherAssetsNoncurrent      
Operating lease, liability $ 68,444,000 $ 68,444,000      
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 $ 250,000,000.0      
2019 Share Repurchase Program [Member]          
Significant Accounting Policies [Line Items]          
Stock repurchased and retired during period, shares | shares 930,105 1,151,914      
Stock repurchased and retired during period, value $ 134,100,000 $ 164,700,000      
Stock repurchase program, remaining authorized repurchase amount $ 317,000,000.0 $ 317,000,000.0      
2019 Share Repurchase Program [Member] | Maximum [Member]          
Significant Accounting Policies [Line Items]          
Stock repurchase program, authorized amount     $ 350,000,000.0