Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Income - Share Repurchases - Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract]
Authorized amount				$ 200,000,000.0
Number of shares repurchased during period (in shares)		0		2,294,235
Shares repurchased during period	$ 23,095,000		$ 55,057,000	$ 55,100,000
Stock repurchase fees				$ 100,000
Remaining authorized repurchase amount		$ 144,900,000