Redeemable Preferred Stocks - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Class Of Stock [Line Items]
Fair value of the embedded derivative	$ 1,843		$ 1,642
Non-Operating Other Expense (Income) [Member]
Class Of Stock [Line Items]
Unrealized loss on change in fair value of the embedded derivative	200
Unrealized gain on change in fair value of the embedded derivative		$ 800
Other Noncurrent Accrued and Other Liabilities [Member]
Class Of Stock [Line Items]
Fair value of the embedded derivative	$ 1,800		$ 1,600
Embedded Derivative [Member]
Class Of Stock [Line Items]
Participating right in dividends and liquidating distributions expressed in number of common shares	303,646		303,646
Embedded Derivative [Member] | Common Stock Shares [Member]
Class Of Stock [Line Items]
Common stock per share	$ 6.24		$ 5.52
Series E Redeemable Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock cumulative dividend rate	14.00%
Participating right in dividends and liquidating distributions expressed in number of common shares	303,646
Series F Redeemable Preferred Stock [Member]
Class Of Stock [Line Items]
Common stock voting rights shares	456,225