Subsequent Event Subsequent Event (Details) |
3 Months Ended | 12 Months Ended | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Feb. 02, 2017
USD ($)
|
Mar. 31, 2017
USD ($)
|
Dec. 31, 2016
USD ($)
|
Sep. 30, 2016
USD ($)
|
Jun. 30, 2016
USD ($)
|
Mar. 31, 2016
USD ($)
|
Dec. 31, 2015
USD ($)
|
Jun. 30, 2015
USD ($)
|
Mar. 31, 2015
USD ($)
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2015
USD ($)
|
Dec. 31, 2014
USD ($)
|
Dec. 31, 2013
USD ($)
|
Dec. 31, 2012
USD ($)
|
Dec. 31, 2011
USD ($)
|
Jan. 31, 2017
USD ($)
|
|
| Subsequent Event [Line Items] | ||||||||||||||||
| Charges | $ 1,148,000 | $ 508,000 | $ 689,000 | $ 102,000 | $ 1,031,000 | $ 689,000 | $ 240,000 | $ 2,447,000 | $ 1,971,000 | $ 11,112,000 | $ 9,336,000 | $ 11,395,000 | $ 10,534,000 | |||
| Convertible Subordinated Debt | Convertible senior subordinated debentures at 4.125%, due in February 2027 | ||||||||||||||||
| Subsequent Event [Line Items] | ||||||||||||||||
| Debt Instrument, Unamortized Discount | $ 311,000 | 1,203,000 | $ 311,000 | 1,203,000 | ||||||||||||
| Interest rate (as a percent) | 4.125% | 4.125% | ||||||||||||||
| Interest Expense | $ 892,000 | 796,000 | 710,000 | |||||||||||||
| Principal amount of liability component | $ 13,350,000 | $ 13,350,000 | 13,350,000 | 13,350,000 | ||||||||||||
| Convertible Subordinated Debt | Convertible senior subordinated debentures at 4.125%, due in February 2027 | Subsequent Event | ||||||||||||||||
| Subsequent Event [Line Items] | ||||||||||||||||
| Interest rate (as a percent) | 4.125% | |||||||||||||||
| Interest Expense | $ 207,000 | |||||||||||||||
| Severance | ||||||||||||||||
| Subsequent Event [Line Items] | ||||||||||||||||
| Charges | $ 1,962,000 | $ 1,678,000 | $ 9,841,000 | $ 8,282,000 | $ 6,775,000 | $ 8,352,000 | ||||||||||
| Severance | Subsequent Event | ||||||||||||||||
| Subsequent Event [Line Items] | ||||||||||||||||
| Associates Impacted, number | 100 | |||||||||||||||
| Charges | $ 2,200,000 | |||||||||||||||
| Restructuring Charges, annualized savings | $ 6,600,000 | |||||||||||||||