Quarterly report pursuant to Section 13 or 15(d)

Organization and Basis of Presentation - Narrative (Details)

v3.19.1
Organization and Basis of Presentation - Narrative (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Oct. 01, 2018
Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Retained earnings $ 705,824 $ 666,210 $ 633,281
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Retained earnings $ 33,927 $ 32,929