Securities Financing Including Redeemable Preferred Stocks- Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Class Of Stock [Line Items]
Common stock issued	27,137,599	27,131,724
Number of common shares into which warrants may be converted	4,103,746
Common stock, par value	$ 0.10
Warrants, last exercisable date	Dec. 04, 2025
Liquidated damages percentage	0.25%
Additional liquidated damages percentage	0.25%
Maximum increase of liquidated damages	1.00%
Aggregate liquidated damages percentage	3.00%
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	456,225
Participating right in dividends and liquidating distributions expressed as a percentage of common shares	2.00%
Minimum percentage of stock holding required	10.00%
Liquidation preference per share	$ 1,000
Series F Redeemable Preferred Stock [Member]
Class Of Stock [Line Items]
Common stock voting rights shares	4,559,971
Voting rights description	The Series F Redeemable Preferred has voting rights (the “Series F Voting Rights”) to vote as a single class on all matters which the common stock have the right to vote and is entitled to a number of votes equal to 4,559,971 shares of our common stock, however, the number of votes that may be cast by the Series F Redeemable Preferred will be reduced automatically upon the occurrence of certain specified events.
Private Placement [Member] | Warrants to Purchase [Member]
Class Of Stock [Line Items]
Common stock issued		4,103,746
Private Placement [Member] | Series E Redeemable Preferred Stock [Member]
Class Of Stock [Line Items]
Value of shares under purchase agreement		$ 210,000,000