Stock-Based Compensation (Narratives) (Details) - USD ($) | 3 Months Ended |
Mar. 31, 2017 | Mar. 31, 2016 |
Stock-based Compensation Arrangements [Line Items] | | |
Equity Compensation Plan, Aggregate Number of Shares Authorized | 1,200,000 | |
Equity Compensation Plan, Number of Shares Available for Grant | 422,659 | |
Number of Shares, Stock Options Granted | 115,883 | |
Stock-based Compensation Expense | $ 1,000,000 | $ 700,000 |
Stock Options Exercised, Number of Shares | 30,253 | |
Tax Benefit from Stock-based Compensation | $ 300,000 | |
Excess Tax Deficit Stock Based Payment Arrangements | | $ 100,000 |
Common Stock Closing Price Per Share | $ 25.75 | |
Stock Options [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Number of Shares, Stock Options Granted | 115,883 | 0 |
Stock-based Compensation Expense | $ 0 | $ 0 |
Stock Options Exercised, Number of Shares | 30,253 | 0 |
Stock Options Exercised, Total Intrinsic Value | $ 300,000 | $ 0 |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Incremental Cost at Maximum Performance | $ 800,000 | |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Period for Recognition of Incremental Cost at Maximum Performance in Years | 2 years | |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Portion Subject to Pre-expiration Vesting | $ 100,000 | |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Portion Subject to Pre-expiration Vesting, Period for Recognition, in Years | 1 month | |
Weighted average fair value of options granted | $ 6.56 | |
Stock Options [Member] | Director [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 1 year | |
Stock Options [Member] | Minimum [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Equity Compensation Plan, Grant Original Contractual Term in Years | 7 years | |
Stock-based Awards, Vesting Period in Years | 3 years | |
Stock Options [Member] | Maximum [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Equity Compensation Plan, Grant Original Contractual Term in Years | 10 years | |
Stock-based Awards, Vesting Period in Years | 4 years | |
Restricted Stock [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Equity Compensation Plan, Aggregate Number of Shares Authorized | 1,000,000 | |
Equity Compensation Plan, Number of Shares Available for Grant | 338,542 | |
Stock-based Compensation Expense | $ 900,000 | 700,000 |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards | $ 3,300,000 | |
Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Period for Recognition in Years | 3 years 8 months | |
Stock-based Awards Other Than Options, Subject to Performance Acceleration, Grants in Period | 0 | |
Stock-based Awards, Grants in Period, Aggregate Grant Date Fair Value | $ 100,000 | 1,800,000 |
Stock-based Compensation Expense Due to Performance Acceleration | 600,000 | 400,000 |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Portion Subject to Acceleration | $ 800,000 | |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Portion Subject to Acceleration, Period for Recognition, in Years | 1 year 5 months | |
Stock-based Awards Other Than Options, Additional Grants Contingently Issuable | 32,076 | |
Stock-based Awards Other Than Options, Additional Grants Contingently Issuable Achievement Threshold | 100.00% | |
Stock-based Awards Other than Options, Vested in Period, Total Fair Value | $ 2,200,000 | $ 800,000 |
Restricted Stock [Member] | Minimum [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 3 years | |
Restricted Stock [Member] | Minimum [Member] | Director [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 6 months | |
Restricted Stock [Member] | Maximum [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 10 years | |
Restricted Stock [Member] | Maximum [Member] | Director [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 7 years | |
Performance-Based and Market-Based RSUs [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Compensation Expense | $ 100,000 | |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Incremental Cost at Maximum Performance | $ 3,400,000 | |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Period for Recognition of Incremental Cost at Maximum Performance in Years | 2 years 8 months | |
Stock-based Awards, Grants in Period, Aggregate Grant Date Fair Value | $ 2,400,000 | |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Portion Subject to Acceleration | $ 1,500,000 | |
Total Compensation Cost Not yet Recognized on Nonvested Stock-based Awards, Portion Subject to Acceleration, Period for Recognition, in Years | 3 years | |
Stock-based Awards Other Than Options, Additional Grants Contingently Issuable | 59,032 | |
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments RSUs Grants In Period Weighted Average Grant Date Fair Value | $ 13.32 | |
Performance-Based and Market-Based RSUs [Member] | Minimum [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 1 year | |
Performance-Based and Market-Based RSUs [Member] | Maximum [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 3 years | |
Service-Based RSUs Member [Member] | Minimum [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 3 years | |
Service-Based RSUs Member [Member] | Maximum [Member] | | |
Stock-based Compensation Arrangements [Line Items] | | |
Stock-based Awards, Vesting Period in Years | 4 years | |