Operations and Summary of Significant Accounting Policies - Revision of Prior Period Financial Statements, Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities	$ 378,858			$ 318,094
Liabilities	33,878,372			29,746,748
Retained earnings	1,600,639	$ 1,637,392	$ 1,663,671	1,663,671	$ 1,516,044	$ 1,440,669	$ 1,361,406
Total stockholders’ equity	$ 2,734,755	2,772,596		2,801,321	2,647,071	2,560,718	2,480,308
Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities				287,157
Liabilities				29,715,811
Retained earnings		1,668,329		1,694,608	1,537,425	1,461,893	1,381,492
Total stockholders’ equity		2,803,533		2,832,258	2,668,452	2,581,942	2,500,394
Revision of Prior Period, Error Correction, Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities				30,937
Liabilities				30,937
Retained earnings		30,937		(30,937)	(21,381)	(21,224)	(20,086)
Total stockholders’ equity		$ 30,937		$ (30,937)	$ (21,381)	$ (21,224)	$ (20,086)