Schedule I - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows From Operating Activities:
Net income (loss)	$ 89,476	$ 44,788	$ (202,386)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Net cash (used in) provided by operating activities	348,416	293,935	192,457
Cash Flows From Investing Activities:
Net cash (used in) provided by investing activities	(195,193)	(180,029)	(170,873)
Cash Flows From Financing Activities:
Exercise of stock options	3,795	4,282	11
Dividends paid to common stockholders			(1,500)
Net cash provided by (used in) financing activities	(147,305)	(112,896)	(56,965)
Change in Cash and Cash Equivalents, including Restricted Cash	5,918	1,010	(35,381)
Cash and Cash Equivalents, including Restricted Cash—Beginning of year	35,007	33,997	69,378
Cash and Cash Equivalents, including Restricted Cash—End of year	40,925	35,007	33,997
Parent Company [Member]
Cash Flows From Operating Activities:
Net income (loss)	89,476	44,788	(202,386)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Equity in net (income) loss of subsidiary	(89,476)	(44,788)	202,386
Dividends forfeited from subsidiary-return on capital, net of forfeitures			(31)
Net cash (used in) provided by operating activities			(31)
Cash Flows From Investing Activities:
Dividends (forfeited) received from subsidiary- return of capital, net of forfeitures	(5)	(61)	1,137
Capital contributed to subsidiary from exercises of stock options	(3,696)	(4,230)
Net cash (used in) provided by investing activities	(3,701)	(4,291)	1,137
Cash Flows From Financing Activities:
Exercise of stock options	3,795	4,282
Dividends paid to common stockholders	(61)	(325)	(1,544)
Net cash provided by (used in) financing activities	3,734	3,957	(1,544)
Change in Cash and Cash Equivalents, including Restricted Cash	33	(334)	(438)
Cash and Cash Equivalents, including Restricted Cash—Beginning of year	136	470	908
Cash and Cash Equivalents, including Restricted Cash—End of year	169	136	470
Supplemental Disclosures of Noncash Investing and Financing Activities
Dividends from subsidiary- return of capital, for purchase of treasury stock	150,000	98,032
Dividends declared, but unpaid	$ 17	$ 84	$ 470