Business Combinations - Unaudited Pro Forma Results (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Business Combinations [Abstract]
Total revenues	$ 677,161	$ 648,063	$ 2,010,160	$ 1,900,105
Income before income taxes	159,607	160,623	505,799	449,916
Net income	$ 134,891	$ 122,189	$ 392,964	$ 341,772
Net income per share:
Basic	$ 0.48	$ 0.43	$ 1.39	$ 1.21
Diluted	$ 0.47	$ 0.43	$ 1.38	$ 1.21
Weighted average number of shares outstanding:
Basic	275,515	272,962	273,803	272,425
Diluted	276,933	275,075	275,338	274,529