Equity, Capital and Other Interests - Other - Additional Information (Details)	9 Months Ended
	Sep. 30, 2018 shares
Equity Capital And Other Interests [Abstract]
Additional common shares authorized	13,000,000
Stock repurchase program, number of shares authorized to be repurchased	13,000,000
Stock repurchased and retired during period, shares	0
Stock repurchase program, remaining number of shares authorized to be repurchased	13,000,000