Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Accounts receivable, allowance		$ 1,391	$ 955
Accumulated depreciation	[1]	47,267	34,107
Accumulated amortization		$ 53,965	$ 59,594
Common Stock, par value
Common Stock, shares authorized		55,000,000	55,000,000
Common Stock, shares issued		36,534,464	36,321,775
Common Stock, shares outstanding		36,534,464	36,321,775

[1] Includes accumulated amortization of capital lease obligations.