Commitments and Contingencies - Additional Information (Detail) - USD ($)
$ in Thousands |
|
3 Months Ended |
6 Months Ended |
12 Months Ended |
|
Oct. 18, 2016 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Sep. 30, 2016 |
Mar. 31, 2016 |
Jun. 30, 2016 |
Dec. 31, 2016 |
Dec. 31, 2015 |
| Loss Contingencies [Line Items] |
|
|
|
|
|
|
|
|
| Insurance proceeds in restricted cash reclassified from other receivables |
|
|
|
|
|
$ 29,571
|
|
|
| Restricted cash |
|
|
|
|
|
|
$ 18,251
|
|
| Securities and Exchange Commission Actions [Member] |
|
|
|
|
|
|
|
|
| Loss Contingencies [Line Items] |
|
|
|
|
|
|
|
|
| Attorneys' fee and litigation expenses |
|
|
$ 3,000
|
|
|
|
|
|
| Settlement charge paid |
|
$ 3,000
|
|
|
|
|
|
|
| Shareholder Derivative Actions [Member] |
|
|
|
|
|
|
|
|
| Loss Contingencies [Line Items] |
|
|
|
|
|
|
|
|
| Attorneys' fee and litigation expenses |
$ 750
|
|
|
|
|
|
|
|
| Proceeds from insurance settlement |
|
|
|
|
$ 3,000
|
|
|
|
| Insurance proceeds in restricted cash reclassified from other receivables |
|
|
|
|
|
|
3,078
|
|
| Litigation settlement paid from escrow |
$ 750
|
|
|
|
|
|
$ 2,258
|
|
| Securities Class Action Complaints [Member] |
|
|
|
|
|
|
|
|
| Loss Contingencies [Line Items] |
|
|
|
|
|
|
|
|
| Proceeds from insurance settlement |
|
|
|
|
29,571
|
|
|
|
| Insurance proceeds in restricted cash reclassified from other receivables |
|
|
|
|
$ 29,571
|
|
|
|
| Disbursements of accrued claims and settlements |
|
|
|
$ 23,500
|
|
|
|
|
| Restricted cash |
|
|
|
$ 6,114
|
|
|
|
|
| Securities Class Action Complaints [Member] | Accrued Expense [Member] |
|
|
|
|
|
|
|
|
| Loss Contingencies [Line Items] |
|
|
|
|
|
|
|
|
| Accrued claim settlement |
|
|
|
|
|
|
|
$ 23,500
|
| Securities Class Action Complaints [Member] | Other Receivables [Member] |
|
|
|
|
|
|
|
|
| Loss Contingencies [Line Items] |
|
|
|
|
|
|
|
|
| Insurance receivable |
|
|
|
|
|
|
|
$ 29,571
|